EP ALGEBRA FOUND.:PREALG.-MYLABMATH ACC
EP ALGEBRA FOUND.:PREALG.-MYLABMATH ACC
2nd Edition
ISBN: 9780135757987
Author: Martin-Gay
Publisher: PEARSON CO
bartleby

Concept explainers

Contingency Table
A contingency table can be defined as the visual representation of the relationship between two or more categorical variables that can be evaluated and registered. It is a categorical version of the scatterplot, which is used to investigate the linear re…
Binomial Distribution
Binomial is an algebraic expression of the sum or the difference of two terms. Before knowing about binomial distribution, we must know about the binomial theorem.
bartleby

Videos

Question
Book Icon
Chapter 11.1, Problem 69ES
To determine

To find using below graph, between what pair of years did the number of digital 3-D cinema screens equal the number of analog cinema screen.

Expert Solution & Answer
Check Mark

Want to see the full answer?

Check out a sample textbook solution
Blurred answer
Previous
Chapter 11.1, Problem 68ES
Next
Chapter 11.1, Problem 70ES
Students have asked these similar questions
Would you please explain step 2?
Evaluate the expression using the given figure to obtain either a or B. 35 - 1 (a) tan 12 12 -1 (b) sin 37 35 (c) arccos 37 35 - 1 (a) tan 12 12 - 1 (b) sin 37 35 (c) arccos 37 ||
I need help

Chapter 11 Solutions

EP ALGEBRA FOUND.:PREALG.-MYLABMATH ACC

Ch. 11.1 - Prob. 1VRVCCh. 11.1 - Prob. 2VRVCCh. 11.1 - Prob. 3VRVCCh. 11.1 - Prob. 4VRVCCh. 11.1 - Prob. 5VRVCCh. 11.1 - Prob. 6VRVCCh. 11.1 - Prob. 1ESCh. 11.1 - Prob. 2ESCh. 11.1 - Prob. 3ESCh. 11.1 - Prob. 4ES
Ch. 11.1 - Prob. 5ESCh. 11.1 - Prob. 6ESCh. 11.1 - Prob. 7ESCh. 11.1 - Prob. 8ESCh. 11.1 - Prob. 9ESCh. 11.1 - Objective A Determine whether each ordered pair is...Ch. 11.1 - Prob. 11ESCh. 11.1 - Prob. 12ESCh. 11.1 - Prob. 13ESCh. 11.1 - Prob. 14ESCh. 11.1 - Prob. 15ESCh. 11.1 - Prob. 16ESCh. 11.1 - Prob. 17ESCh. 11.1 - Prob. 18ESCh. 11.1 - Prob. 19ESCh. 11.1 - Prob. 20ESCh. 11.1 - Prob. 21ESCh. 11.1 - Prob. 22ESCh. 11.1 - Prob. 23ESCh. 11.1 - Prob. 24ESCh. 11.1 - Prob. 25ESCh. 11.1 - Prob. 26ESCh. 11.1 - Prob. 27ESCh. 11.1 - Prob. 28ESCh. 11.1 - Prob. 29ESCh. 11.1 - Prob. 30ESCh. 11.1 - Prob. 31ESCh. 11.1 - Prob. 32ESCh. 11.1 - Prob. 33ESCh. 11.1 - Prob. 34ESCh. 11.1 - Prob. 35ESCh. 11.1 - Prob. 36ESCh. 11.1 - Prob. 37ESCh. 11.1 - Prob. 38ESCh. 11.1 - Prob. 39ESCh. 11.1 - Prob. 40ESCh. 11.1 - Prob. 41ESCh. 11.1 - Prob. 42ESCh. 11.1 - Prob. 43ESCh. 11.1 - Prob. 44ESCh. 11.1 - Prob. 45ESCh. 11.1 - Prob. 46ESCh. 11.1 - Prob. 47ESCh. 11.1 - Prob. 48ESCh. 11.1 - Prob. 49ESCh. 11.1 - Prob. 50ESCh. 11.1 - Prob. 51ESCh. 11.1 - Prob. 52ESCh. 11.1 - Prob. 53ESCh. 11.1 - Prob. 54ESCh. 11.1 - Prob. 55ESCh. 11.1 - Prob. 56ESCh. 11.1 - Prob. 57ESCh. 11.1 - Prob. 58ESCh. 11.1 - Prob. 59ESCh. 11.1 - Prob. 60ESCh. 11.1 - Prob. 61ESCh. 11.1 - Prob. 62ESCh. 11.1 - Prob. 63ESCh. 11.1 - Prob. 64ESCh. 11.1 - Prob. 65ESCh. 11.1 - Prob. 66ESCh. 11.1 - Prob. 67ESCh. 11.1 - Prob. 68ESCh. 11.1 - Prob. 69ESCh. 11.1 - Prob. 70ESCh. 11.1 - Prob. 71ESCh. 11.1 - Prob. 72ESCh. 11.1 - Prob. 73ESCh. 11.1 - Prob. 74ESCh. 11.1 - Below are tables of values for two linear...Ch. 11.1 - Prob. 76ESCh. 11.1 - Prob. 77ESCh. 11.1 - Prob. 78ESCh. 11.2 - Prob. 1VRVCCh. 11.2 - Prob. 2VRVCCh. 11.2 - Prob. 3VRVCCh. 11.2 - Prob. 4VRVCCh. 11.2 - Prob. 5VRVCCh. 11.2 - Prob. 6VRVCCh. 11.2 - Prob. 1ESCh. 11.2 - Prob. 2ESCh. 11.2 - Prob. 3ESCh. 11.2 - Prob. 4ESCh. 11.2 - Prob. 5ESCh. 11.2 - Prob. 6ESCh. 11.2 - Prob. 7ESCh. 11.2 - Prob. 8ESCh. 11.2 - Prob. 9ESCh. 11.2 - Prob. 10ESCh. 11.2 - Prob. 11ESCh. 11.2 - Prob. 12ESCh. 11.2 - Prob. 13ESCh. 11.2 - Prob. 14ESCh. 11.2 - Prob. 15ESCh. 11.2 - Prob. 16ESCh. 11.2 - Prob. 17ESCh. 11.2 - Prob. 18ESCh. 11.2 - Prob. 19ESCh. 11.2 - Prob. 20ESCh. 11.2 - Solve each system of equations by the substitution...Ch. 11.2 - Solve each system of equations by the substitution...Ch. 11.2 - Prob. 23ESCh. 11.2 - Prob. 24ESCh. 11.2 - Prob. 25ESCh. 11.2 - Prob. 26ESCh. 11.2 - Prob. 27ESCh. 11.2 - Prob. 28ESCh. 11.2 - Prob. 29ESCh. 11.2 - Prob. 30ESCh. 11.2 - Prob. 31ESCh. 11.2 - Prob. 32ESCh. 11.2 - Prob. 33ESCh. 11.2 - Prob. 34ESCh. 11.2 - Prob. 35ESCh. 11.2 - Prob. 36ESCh. 11.2 - Prob. 37ESCh. 11.2 - Prob. 38ESCh. 11.2 - Prob. 39ESCh. 11.2 - Prob. 40ESCh. 11.2 - Prob. 41ESCh. 11.2 - Prob. 42ESCh. 11.2 - Prob. 43ESCh. 11.2 - Prob. 44ESCh. 11.2 - Prob. 45ESCh. 11.2 - Prob. 46ESCh. 11.2 - Prob. 47ESCh. 11.2 - Prob. 48ESCh. 11.2 - Prob. 49ESCh. 11.2 - Prob. 50ESCh. 11.2 - Prob. 51ESCh. 11.2 - Prob. 52ESCh. 11.2 - Prob. 53ESCh. 11.2 - Prob. 54ESCh. 11.2 - Solve each system by substitution. When necessary,...Ch. 11.2 - Prob. 56ESCh. 11.2 - Prob. 57ESCh. 11.2 - Prob. 58ESCh. 11.3 - Prob. 1VRVCCh. 11.3 - Prob. 2VRVCCh. 11.3 - Prob. 3VRVCCh. 11.3 - Prob. 4VRVCCh. 11.3 - Prob. 1ESCh. 11.3 - Prob. 2ESCh. 11.3 - Prob. 3ESCh. 11.3 - Prob. 4ESCh. 11.3 - Prob. 5ESCh. 11.3 - Prob. 6ESCh. 11.3 - Prob. 7ESCh. 11.3 - Prob. 8ESCh. 11.3 - Prob. 9ESCh. 11.3 - Prob. 10ESCh. 11.3 - Prob. 11ESCh. 11.3 - Prob. 12ESCh. 11.3 - Prob. 13ESCh. 11.3 - Prob. 14ESCh. 11.3 - Prob. 15ESCh. 11.3 - Prob. 16ESCh. 11.3 - Prob. 17ESCh. 11.3 - Prob. 18ESCh. 11.3 - Prob. 19ESCh. 11.3 - Prob. 20ESCh. 11.3 - Prob. 21ESCh. 11.3 - Prob. 22ESCh. 11.3 - Prob. 23ESCh. 11.3 - Prob. 24ESCh. 11.3 - Prob. 25ESCh. 11.3 - Prob. 26ESCh. 11.3 - Prob. 27ESCh. 11.3 - Prob. 28ESCh. 11.3 - Prob. 29ESCh. 11.3 - Prob. 30ESCh. 11.3 - Prob. 31ESCh. 11.3 - Prob. 32ESCh. 11.3 - Prob. 33ESCh. 11.3 - Prob. 34ESCh. 11.3 - Prob. 35ESCh. 11.3 - Prob. 36ESCh. 11.3 - Prob. 37ESCh. 11.3 - Prob. 38ESCh. 11.3 - Prob. 39ESCh. 11.3 - Prob. 40ESCh. 11.3 - Prob. 41ESCh. 11.3 - Prob. 42ESCh. 11.3 - Prob. 43ESCh. 11.3 - Prob. 44ESCh. 11.3 - Prob. 45ESCh. 11.3 - Prob. 46ESCh. 11.3 - Prob. 47ESCh. 11.3 - Prob. 48ESCh. 11.3 - Prob. 49ESCh. 11.3 - Prob. 50ESCh. 11.3 - Prob. 51ESCh. 11.3 - Prob. 52ESCh. 11.3 - Prob. 53ESCh. 11.3 - Prob. 54ESCh. 11.3 - Prob. 55ESCh. 11.3 - Prob. 56ESCh. 11.3 - Prob. 57ESCh. 11.3 - Prob. 58ESCh. 11.3 - Prob. 59ESCh. 11.3 - Prob. 60ESCh. 11.3 - Prob. 61ESCh. 11.3 - Prob. 62ESCh. 11.3 - Prob. 63ESCh. 11.3 - Prob. 64ESCh. 11.3 - Prob. 65ESCh. 11.3 - Prob. 66ESCh. 11.3 - Prob. 67ESCh. 11.3 - Prob. 68ESCh. 11.3 - Prob. 69ESCh. 11.3 - Prob. 70ESCh. 11.3 - Prob. 71ESCh. 11.3 - Prob. 72ESCh. 11.3 - Solve. In recent years, budgets for advertising on...Ch. 11.3 - Prob. 74ESCh. 11.4 - Prob. 1VRVCCh. 11.4 - Prob. 2VRVCCh. 11.4 - Prob. 3VRVCCh. 11.4 - Prob. 4VRVCCh. 11.4 - Prob. 1ESCh. 11.4 - Prob. 2ESCh. 11.4 - Prob. 3ESCh. 11.4 - Prob. 4ESCh. 11.4 - Prob. 5ESCh. 11.4 - Prob. 6ESCh. 11.4 - Prob. 7ESCh. 11.4 - Prob. 8ESCh. 11.4 - Prob. 9ESCh. 11.4 - Prob. 10ESCh. 11.4 - Prob. 11ESCh. 11.4 - Prob. 12ESCh. 11.4 - Prob. 13ESCh. 11.4 - Prob. 14ESCh. 11.4 - Prob. 15ESCh. 11.4 - Prob. 16ESCh. 11.4 - Solve each system. See Examples 1 through 5. 17....Ch. 11.4 - Prob. 18ESCh. 11.4 - Prob. 19ESCh. 11.4 - Prob. 20ESCh. 11.4 - Prob. 21ESCh. 11.4 - Prob. 22ESCh. 11.4 - Prob. 23ESCh. 11.4 - Prob. 24ESCh. 11.4 - Prob. 25ESCh. 11.4 - Prob. 26ESCh. 11.4 - Prob. 27ESCh. 11.4 - Prob. 28ESCh. 11.4 - Prob. 29ESCh. 11.4 - Prob. 30ESCh. 11.4 - Prob. 31ESCh. 11.4 - Prob. 32ESCh. 11.4 - Prob. 33ESCh. 11.4 - Prob. 34ESCh. 11.4 - Prob. 35ESCh. 11.4 - Prob. 36ESCh. 11.4 - Prob. 37ESCh. 11.4 - Prob. 38ESCh. 11.4 - Prob. 39ESCh. 11.4 - Prob. 40ESCh. 11.4 - Prob. 41ESCh. 11.4 - Prob. 42ESCh. 11.4 - Prob. 43ESCh. 11.4 - Prob. 44ESCh. 11.4 - Prob. 45ESCh. 11.4 - Prob. 46ESCh. 11.5 - Prob. 1ESCh. 11.5 - Prob. 2ESCh. 11.5 - Prob. 3ESCh. 11.5 - Prob. 4ESCh. 11.5 - Prob. 5ESCh. 11.5 - Prob. 6ESCh. 11.5 - Prob. 7ESCh. 11.5 - Prob. 8ESCh. 11.5 - Prob. 9ESCh. 11.5 - Prob. 10ESCh. 11.5 - Prob. 11ESCh. 11.5 - Prob. 12ESCh. 11.5 - Prob. 13ESCh. 11.5 - Prob. 14ESCh. 11.5 - Prob. 15ESCh. 11.5 - Prob. 16ESCh. 11.5 - Prob. 17ESCh. 11.5 - Prob. 18ESCh. 11.5 - Prob. 19ESCh. 11.5 - Prob. 20ESCh. 11.5 - Prob. 21ESCh. 11.5 - Prob. 22ESCh. 11.5 - Prob. 23ESCh. 11.5 - Prob. 24ESCh. 11.5 - Prob. 25ESCh. 11.5 - Prob. 26ESCh. 11.5 - Prob. 27ESCh. 11.5 - Prob. 28ESCh. 11.5 - Prob. 29ESCh. 11.5 - Prob. 30ESCh. 11.5 - Prob. 31ESCh. 11.5 - Prob. 32ESCh. 11.5 - Prob. 33ESCh. 11.5 - Prob. 34ESCh. 11.5 - Prob. 35ESCh. 11.5 - Prob. 36ESCh. 11.5 - Prob. 37ESCh. 11.5 - Prob. 38ESCh. 11.5 - Prob. 39ESCh. 11.5 - Prob. 40ESCh. 11.5 - Prob. 41ESCh. 11.5 - A charily fund-raiser consisted of a spaghetti...Ch. 11.5 - Prob. 43ESCh. 11.5 - Prob. 44ESCh. 11.5 - Prob. 45ESCh. 11.5 - Prob. 46ESCh. 11.5 - Prob. 47ESCh. 11.5 - Prob. 48ESCh. 11.5 - Prob. 49ESCh. 11.5 - The rate of fatalities per 100 million...Ch. 11.5 - Prob. 51ESCh. 11.5 - Prob. 52ESCh. 11.5 - Prob. 53ESCh. 11.5 - Prob. 54ESCh. 11.5 - Prob. 55ESCh. 11.5 - Prob. 56ESCh. 11.5 - Objective B Given the cost function C(x) and the...Ch. 11.5 - Objective B Given the cost function C(x) and the...Ch. 11.5 - Prob. 59ESCh. 11.5 - Prob. 60ESCh. 11.5 - Prob. 61ESCh. 11.5 - Prob. 62ESCh. 11.5 - Prob. 63ESCh. 11.5 - Prob. 64ESCh. 11.5 - Prob. 65ESCh. 11.5 - Prob. 66ESCh. 11.5 - Prob. 67ESCh. 11.5 - Prob. 68ESCh. 11.5 - Prob. 69ESCh. 11.5 - Prob. 70ESCh. 11.5 - Prob. 71ESCh. 11.5 - Prob. 72ESCh. 11.5 - Prob. 73ESCh. 11.5 - Prob. 74ESCh. 11.5 - Prob. 75ESCh. 11.5 - Prob. 76ESCh. 11.5 - Prob. 77ESCh. 11.5 - Prob. 78ESCh. 11.5 - Prob. 79ESCh. 11.5 - Prob. 80ESCh. 11.5 - Prob. 81ESCh. 11.5 - Prob. 82ESCh. 11.5 - Prob. 83ESCh. 11.5 - Prob. 84ESCh. 11.5 - Prob. 85ESCh. 11.5 - Prob. 86ESCh. 11 - Solve each system by either the addition method or...Ch. 11 - Prob. 2IRCh. 11 - Prob. 3IRCh. 11 - Prob. 4IRCh. 11 - Prob. 5IRCh. 11 - Prob. 6IRCh. 11 - Prob. 7IRCh. 11 - Prob. 8IRCh. 11 - Prob. 9IRCh. 11 - Prob. 10IRCh. 11 - Prob. 11IRCh. 11 - Prob. 12IRCh. 11 - Prob. 13IRCh. 11 - Prob. 14IRCh. 11 - Prob. 15IRCh. 11 - Prob. 16IRCh. 11 - Prob. 17IRCh. 11 - Prob. 18IRCh. 11 - Prob. 19IRCh. 11 - Prob. 20IRCh. 11 - Prob. 21IRCh. 11 - Prob. 22IRCh. 11 - Prob. 1VCCh. 11 - Prob. 2VCCh. 11 - Prob. 3VCCh. 11 - Prob. 4VCCh. 11 - Prob. 5VCCh. 11 - Prob. 6VCCh. 11 - Prob. 7VCCh. 11 - Prob. 1RCh. 11 - Prob. 2RCh. 11 - Prob. 3RCh. 11 - Prob. 4RCh. 11 - Prob. 5RCh. 11 - Prob. 6RCh. 11 - Prob. 7RCh. 11 - Prob. 8RCh. 11 - Prob. 9RCh. 11 - Prob. 10RCh. 11 - Prob. 11RCh. 11 - Prob. 12RCh. 11 - Prob. 13RCh. 11 - Prob. 14RCh. 11 - Prob. 15RCh. 11 - Prob. 16RCh. 11 - Prob. 17RCh. 11 - Prob. 18RCh. 11 - Prob. 19RCh. 11 - Prob. 20RCh. 11 - Prob. 21RCh. 11 - Solve each system of equations by the addition...Ch. 11 - Prob. 23RCh. 11 - Prob. 24RCh. 11 - Prob. 25RCh. 11 - Prob. 26RCh. 11 - Prob. 27RCh. 11 - Prob. 28RCh. 11 - Prob. 29RCh. 11 - Prob. 30RCh. 11 - Prob. 31RCh. 11 - Prob. 32RCh. 11 - Prob. 33RCh. 11 - Prob. 34RCh. 11 - Prob. 35RCh. 11 - Prob. 36RCh. 11 - Prob. 37RCh. 11 - Prob. 38RCh. 11 - Prob. 39RCh. 11 - Prob. 40RCh. 11 - Prob. 41RCh. 11 - Prob. 42RCh. 11 - Prob. 43RCh. 11 - Solve each problem by writing and solving a system...Ch. 11 - Prob. 45RCh. 11 - Prob. 46RCh. 11 - Prob. 47RCh. 11 - Prob. 48RCh. 11 - Prob. 49RCh. 11 - Prob. 50RCh. 11 - Prob. 51RCh. 11 - Prob. 52RCh. 11 - Prob. 53RCh. 11 - Prob. 54RCh. 11 - Prob. 55RCh. 11 - Prob. 56RCh. 11 - Prob. 57RCh. 11 - Prob. 58RCh. 11 - Prob. 59RCh. 11 - Prob. 60RCh. 11 - Solve each problem by writing and solving a system...Ch. 11 - Prob. 62RCh. 11 - Prob. 63RCh. 11 - Prob. 1GRTCh. 11 - Prob. 2GRTCh. 11 - Prob. 3GRTCh. 11 - Prob. 4GRTCh. 11 - Prob. 5GRTCh. 11 - Prob. 6GRTCh. 11 - Prob. 7GRTCh. 11 - Prob. 8GRTCh. 11 - Prob. 9GRTCh. 11 - Prob. 10GRTCh. 11 - Prob. 11GRTCh. 11 - Prob. 12GRTCh. 11 - Prob. 1TCh. 11 - Prob. 2TCh. 11 - Prob. 3TCh. 11 - Prob. 4TCh. 11 - Prob. 5TCh. 11 - Prob. 6TCh. 11 - Prob. 7TCh. 11 - Prob. 8TCh. 11 - Prob. 9TCh. 11 - Prob. 10TCh. 11 - Prob. 11TCh. 11 - Prob. 12TCh. 11 - Prob. 13TCh. 11 - Prob. 14TCh. 11 - Prob. 15TCh. 11 - Prob. 16TCh. 11 - Prob. 17TCh. 11 - Prob. 18TCh. 11 - Prob. 19TCh. 11 - Prob. 20TCh. 11 - Prob. 21TCh. 11 - Prob. 1CRCh. 11 - Prob. 2CRCh. 11 - Prob. 3CRCh. 11 - Prob. 4CRCh. 11 - Prob. 5CRCh. 11 - Prob. 6CRCh. 11 - Prob. 7CRCh. 11 - Prob. 8CRCh. 11 - Prob. 9CRCh. 11 - Prob. 10CRCh. 11 - Prob. 11CRCh. 11 - Prob. 12CRCh. 11 - Prob. 13CRCh. 11 - Prob. 14CRCh. 11 - Prob. 15CRCh. 11 - Prob. 16CRCh. 11 - Prob. 17CRCh. 11 - Solve P=a+b+c for b.Ch. 11 - Prob. 19CRCh. 11 - Prob. 20CRCh. 11 - Prob. 21CRCh. 11 - Prob. 22CRCh. 11 - Prob. 23CRCh. 11 - Prob. 24CRCh. 11 - Prob. 25CRCh. 11 - Prob. 26CRCh. 11 - Prob. 27CRCh. 11 - Prob. 28CRCh. 11 - Prob. 29CRCh. 11 - Prob. 30CRCh. 11 - Prob. 31CRCh. 11 - Prob. 32CRCh. 11 - Prob. 33CRCh. 11 - Prob. 34CRCh. 11 - Prob. 35CRCh. 11 - Prob. 36CRCh. 11 - Solve the system. 37. {x+2y=72x+2y=13Ch. 11 - Prob. 38CRCh. 11 - Prob. 39CRCh. 11 - Prob. 40CRCh. 11 - Prob. 41CRCh. 11 - Prob. 42CRCh. 11 - Prob. 43CRCh. 11 - Prob. 44CR
Knowledge Booster
Background pattern image
Algebra
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, algebra and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Text book image
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Text book image
Algebra for College Students
Algebra
ISBN:9781285195780
Author:Jerome E. Kaufmann, Karen L. Schwitters
Publisher:Cengage Learning
Text book image
Intermediate Algebra
Algebra
ISBN:9781285195728
Author:Jerome E. Kaufmann, Karen L. Schwitters
Publisher:Cengage Learning
Text book image
Holt Mcdougal Larson Pre-algebra: Student Edition...
Algebra
ISBN:9780547587776
Author:HOLT MCDOUGAL
Publisher:HOLT MCDOUGAL
Text book image
College Algebra
Algebra
ISBN:9781337282291
Author:Ron Larson
Publisher:Cengage Learning
Text book image
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
SEE MORE TEXTBOOKS
Mod-01 Lec-01 Discrete probability distributions (Part 1); Author: nptelhrd;https://www.youtube.com/watch?v=6x1pL9Yov1k;License: Standard YouTube License, CC-BY
Discrete Probability Distributions; Author: Learn Something;https://www.youtube.com/watch?v=m9U4UelWLFs;License: Standard YouTube License, CC-BY
Probability Distribution Functions (PMF, PDF, CDF); Author: zedstatistics;https://www.youtube.com/watch?v=YXLVjCKVP7U;License: Standard YouTube License, CC-BY
Discrete Distributions: Binomial, Poisson and Hypergeometric | Statistics for Data Science; Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=lHhyy4JMigg;License: Standard Youtube License