EBK PRECALCULUS W/LIMITS
EBK PRECALCULUS W/LIMITS
4th Edition
ISBN: 9781337516853
Author: Larson
Publisher: CENGAGE CO
bartleby

Videos

Question
Book Icon
Chapter A.5, Problem 55E
To determine

To Simplify: The expression 5+33

Expert Solution & Answer
Check Mark

Answer to Problem 55E

  5+33=23(5−3)

Explanation of Solution

Given information:

The expression 5+33

Concept and Formula Used:

Rationalization of numerator by multiplying numerator and denominator by conjugate of the numerator.

Calculation:

The given expression is 5+33

Multiply numerator and denominator by

  5−35+33=5+33×5−35−3Using (a+b)(a−b)=a2−b25+33=(5)2−(3)23(5−3)5+33=5−33(5−3)5+33=23(5−3)

Conclusion:

  5+33=23(5−3)

Previous
Chapter A.5, Problem 54E
Next
Chapter A.5, Problem 56E

Chapter A Solutions

EBK PRECALCULUS W/LIMITS

Ch. A.1 - Prob. 1ECh. A.1 - Prob. 2ECh. A.1 - Prob. 3ECh. A.1 - Prob. 4ECh. A.1 - Prob. 5ECh. A.1 - Prob. 6ECh. A.1 - Prob. 7ECh. A.1 - Prob. 8ECh. A.1 - Prob. 9ECh. A.1 - Prob. 10E
Ch. A.1 - Prob. 11ECh. A.1 - Prob. 12ECh. A.1 - Prob. 13ECh. A.1 - Prob. 14ECh. A.1 - Prob. 15ECh. A.1 - Prob. 16ECh. A.1 - Prob. 17ECh. A.1 - Prob. 18ECh. A.1 - Prob. 19ECh. A.1 - Prob. 20ECh. A.1 - Prob. 21ECh. A.1 - Prob. 22ECh. A.1 - Prob. 23ECh. A.1 - Prob. 24ECh. A.1 - Prob. 25ECh. A.1 - Prob. 26ECh. A.1 - Prob. 27ECh. A.1 - Prob. 28ECh. A.1 - Prob. 29ECh. A.1 - Prob. 30ECh. A.1 - Prob. 31ECh. A.1 - Prob. 32ECh. A.1 - Prob. 33ECh. A.1 - Prob. 34ECh. A.1 - Prob. 35ECh. A.1 - Prob. 36ECh. A.1 - Prob. 37ECh. A.1 - Prob. 38ECh. A.1 - Prob. 39ECh. A.1 - Prob. 40ECh. A.1 - Prob. 41ECh. A.1 - Prob. 42ECh. A.1 - Prob. 43ECh. A.1 - Prob. 44ECh. A.1 - Prob. 45ECh. A.1 - Prob. 46ECh. A.1 - Prob. 47ECh. A.1 - Prob. 48ECh. A.1 - Prob. 49ECh. A.1 - Prob. 50ECh. A.1 - Prob. 51ECh. A.1 - Prob. 52ECh. A.1 - Prob. 53ECh. A.1 - Prob. 54ECh. A.1 - Prob. 55ECh. A.1 - Prob. 56ECh. A.1 - Prob. 57ECh. A.1 - Prob. 58ECh. A.1 - Prob. 59ECh. A.1 - Prob. 60ECh. A.1 - Prob. 61ECh. A.1 - Prob. 62ECh. A.1 - Prob. 63ECh. A.1 - Prob. 64ECh. A.1 - Prob. 65ECh. A.1 - Prob. 66ECh. A.1 - Prob. 67ECh. A.1 - Prob. 68ECh. A.1 - Prob. 69ECh. A.1 - Prob. 70ECh. A.1 - Prob. 71ECh. A.1 - Prob. 72ECh. A.1 - Prob. 73ECh. A.1 - Prob. 74ECh. A.1 - Prob. 75ECh. A.1 - Prob. 76ECh. A.1 - Prob. 77ECh. A.2 - Prob. 1ECh. A.2 - Prob. 2ECh. A.2 - Prob. 3ECh. A.2 - Prob. 4ECh. A.2 - Prob. 5ECh. A.2 - Prob. 6ECh. A.2 - Prob. 7ECh. A.2 - Prob. 8ECh. A.2 - Prob. 9ECh. A.2 - Prob. 10ECh. A.2 - Prob. 11ECh. A.2 - Prob. 12ECh. A.2 - Prob. 13ECh. A.2 - Prob. 14ECh. A.2 - Prob. 15ECh. A.2 - Prob. 16ECh. A.2 - Prob. 17ECh. A.2 - Prob. 18ECh. A.2 - Prob. 19ECh. A.2 - Prob. 20ECh. A.2 - Prob. 21ECh. A.2 - Prob. 22ECh. A.2 - Prob. 23ECh. A.2 - Prob. 24ECh. A.2 - Prob. 25ECh. A.2 - Prob. 26ECh. A.2 - Prob. 27ECh. A.2 - Prob. 28ECh. A.2 - Prob. 29ECh. A.2 - Prob. 30ECh. A.2 - Prob. 31ECh. A.2 - Prob. 32ECh. A.2 - Prob. 33ECh. A.2 - Prob. 34ECh. A.2 - Prob. 35ECh. A.2 - Prob. 36ECh. A.2 - Prob. 37ECh. A.2 - Prob. 38ECh. A.2 - Prob. 39ECh. A.2 - Prob. 40ECh. A.2 - Prob. 41ECh. A.2 - Prob. 42ECh. A.2 - Prob. 43ECh. A.2 - Prob. 44ECh. A.2 - Prob. 45ECh. A.2 - Prob. 46ECh. A.2 - Prob. 47ECh. A.2 - Prob. 48ECh. A.2 - Prob. 49ECh. A.2 - Prob. 50ECh. A.2 - Prob. 51ECh. A.2 - Prob. 52ECh. A.2 - Prob. 53ECh. A.2 - Prob. 54ECh. A.2 - Prob. 55ECh. A.2 - Prob. 56ECh. A.2 - Prob. 57ECh. A.2 - Prob. 58ECh. A.2 - Prob. 59ECh. A.2 - Prob. 60ECh. A.2 - Prob. 61ECh. A.2 - Prob. 62ECh. A.2 - Prob. 63ECh. A.2 - Prob. 64ECh. A.2 - Prob. 65ECh. A.2 - Prob. 66ECh. A.2 - Prob. 67ECh. A.2 - Prob. 68ECh. A.2 - Prob. 69ECh. A.2 - Prob. 70ECh. A.2 - Prob. 71ECh. A.2 - Prob. 72ECh. A.2 - Prob. 73ECh. A.2 - Prob. 74ECh. A.3 - Prob. 1ECh. A.3 - Prob. 2ECh. A.3 - Prob. 3ECh. A.3 - Prob. 4ECh. A.3 - Prob. 5ECh. A.3 - Prob. 6ECh. A.3 - Prob. 7ECh. A.3 - Prob. 8ECh. A.3 - Prob. 9ECh. A.3 - Prob. 10ECh. A.3 - Prob. 11ECh. A.3 - Prob. 12ECh. A.3 - Prob. 13ECh. A.3 - Prob. 14ECh. A.3 - Prob. 15ECh. A.3 - Prob. 16ECh. A.3 - Prob. 17ECh. A.3 - Prob. 18ECh. A.3 - Prob. 19ECh. A.3 - Prob. 20ECh. A.3 - Prob. 21ECh. A.3 - Prob. 22ECh. A.3 - Prob. 23ECh. A.3 - Prob. 24ECh. A.3 - Prob. 25ECh. A.3 - Prob. 26ECh. A.3 - Prob. 27ECh. A.3 - Prob. 28ECh. A.3 - Prob. 29ECh. A.3 - Prob. 30ECh. A.3 - Prob. 31ECh. A.3 - Prob. 32ECh. A.3 - Prob. 33ECh. A.3 - Prob. 34ECh. A.3 - Prob. 35ECh. A.3 - Prob. 36ECh. A.3 - Prob. 37ECh. A.3 - Prob. 38ECh. A.3 - Prob. 39ECh. A.3 - Prob. 40ECh. A.3 - Prob. 41ECh. A.3 - Prob. 42ECh. A.3 - Prob. 43ECh. A.3 - Prob. 44ECh. A.3 - Prob. 45ECh. A.3 - Prob. 46ECh. A.3 - Prob. 47ECh. A.3 - Prob. 48ECh. A.3 - Prob. 49ECh. A.3 - Prob. 50ECh. A.3 - Prob. 51ECh. A.3 - Prob. 52ECh. A.3 - Prob. 53ECh. A.3 - Prob. 54ECh. A.3 - Prob. 55ECh. A.3 - Prob. 56ECh. A.3 - Prob. 57ECh. A.3 - Prob. 58ECh. A.3 - Prob. 59ECh. A.3 - Prob. 60ECh. A.3 - Prob. 61ECh. A.3 - Prob. 62ECh. A.3 - Prob. 63ECh. A.3 - Prob. 64ECh. A.3 - Prob. 65ECh. A.3 - Prob. 66ECh. A.3 - Prob. 67ECh. A.3 - Prob. 68ECh. A.3 - Prob. 69ECh. A.3 - Prob. 70ECh. A.3 - Prob. 71ECh. A.3 - Prob. 72ECh. A.3 - Prob. 73ECh. A.3 - Prob. 74ECh. A.3 - Prob. 75ECh. A.3 - Prob. 76ECh. A.3 - Prob. 77ECh. A.3 - Prob. 78ECh. A.3 - Prob. 79ECh. A.3 - Prob. 80ECh. A.3 - Prob. 81ECh. A.3 - Prob. 82ECh. A.3 - Prob. 83ECh. A.3 - Prob. 84ECh. A.3 - Prob. 85ECh. A.3 - Prob. 86ECh. A.3 - Prob. 87ECh. A.3 - Prob. 88ECh. A.3 - Prob. 89ECh. A.3 - Prob. 90ECh. A.3 - Prob. 91ECh. A.3 - Prob. 92ECh. A.3 - Prob. 93ECh. A.3 - Prob. 94ECh. A.3 - Prob. 95ECh. A.3 - Prob. 96ECh. A.4 - Prob. 1ECh. A.4 - Prob. 2ECh. A.4 - Prob. 3ECh. A.4 - Prob. 4ECh. A.4 - Prob. 5ECh. A.4 - Prob. 6ECh. A.4 - Prob. 7ECh. A.4 - Prob. 8ECh. A.4 - Prob. 9ECh. A.4 - Prob. 10ECh. A.4 - Prob. 11ECh. A.4 - Prob. 12ECh. A.4 - Prob. 13ECh. A.4 - Prob. 14ECh. A.4 - Prob. 15ECh. A.4 - Prob. 16ECh. A.4 - Prob. 17ECh. A.4 - Prob. 18ECh. A.4 - Prob. 19ECh. A.4 - Prob. 20ECh. A.4 - Prob. 21ECh. A.4 - Prob. 22ECh. A.4 - Prob. 23ECh. A.4 - Prob. 24ECh. A.4 - Prob. 25ECh. A.4 - Prob. 26ECh. A.4 - Prob. 27ECh. A.4 - Prob. 28ECh. A.4 - Prob. 29ECh. A.4 - Prob. 30ECh. A.4 - Prob. 31ECh. A.4 - Prob. 32ECh. A.4 - Prob. 33ECh. A.4 - Prob. 34ECh. A.4 - Prob. 35ECh. A.4 - Prob. 36ECh. A.4 - Prob. 37ECh. A.4 - Prob. 38ECh. A.4 - Prob. 39ECh. A.4 - Prob. 40ECh. A.4 - Prob. 41ECh. A.4 - Prob. 42ECh. A.4 - Prob. 43ECh. A.4 - Prob. 44ECh. A.4 - Prob. 45ECh. A.4 - Prob. 46ECh. A.4 - Prob. 47ECh. A.4 - Prob. 48ECh. A.4 - Prob. 49ECh. A.4 - Prob. 50ECh. A.4 - Prob. 51ECh. A.4 - Prob. 52ECh. A.4 - Prob. 53ECh. A.4 - Prob. 54ECh. A.4 - Prob. 55ECh. A.4 - Prob. 56ECh. A.4 - Prob. 57ECh. A.4 - Prob. 58ECh. A.4 - Prob. 59ECh. A.4 - Prob. 60ECh. A.4 - Prob. 61ECh. A.4 - Prob. 62ECh. A.4 - Prob. 63ECh. A.4 - Prob. 64ECh. A.4 - Prob. 65ECh. A.4 - Prob. 66ECh. A.4 - Prob. 67ECh. A.4 - Prob. 68ECh. A.4 - Prob. 69ECh. A.4 - Prob. 70ECh. A.4 - Prob. 71ECh. A.4 - Prob. 72ECh. A.4 - Prob. 73ECh. A.4 - Prob. 74ECh. A.4 - Prob. 75ECh. A.4 - Prob. 76ECh. A.4 - Prob. 77ECh. A.4 - Prob. 78ECh. A.4 - Prob. 79ECh. A.4 - Prob. 80ECh. A.5 - Prob. 1ECh. A.5 - Prob. 2ECh. A.5 - Prob. 3ECh. A.5 - Prob. 4ECh. A.5 - Prob. 5ECh. A.5 - Prob. 6ECh. A.5 - Prob. 7ECh. A.5 - Prob. 8ECh. A.5 - Prob. 9ECh. A.5 - Prob. 10ECh. A.5 - Prob. 11ECh. A.5 - Prob. 12ECh. A.5 - Prob. 13ECh. A.5 - Prob. 14ECh. A.5 - Prob. 15ECh. A.5 - Prob. 16ECh. A.5 - Prob. 17ECh. A.5 - Prob. 18ECh. A.5 - Prob. 19ECh. A.5 - Prob. 20ECh. A.5 - Prob. 21ECh. A.5 - Prob. 22ECh. A.5 - Prob. 23ECh. A.5 - Prob. 24ECh. A.5 - Prob. 25ECh. A.5 - Prob. 26ECh. A.5 - Prob. 27ECh. A.5 - Prob. 28ECh. A.5 - Prob. 29ECh. A.5 - Prob. 30ECh. A.5 - Prob. 31ECh. A.5 - Prob. 32ECh. A.5 - Prob. 33ECh. A.5 - Prob. 34ECh. A.5 - Prob. 35ECh. A.5 - Prob. 36ECh. A.5 - Prob. 37ECh. A.5 - Prob. 38ECh. A.5 - Prob. 39ECh. A.5 - Prob. 40ECh. A.5 - Prob. 41ECh. A.5 - Prob. 42ECh. A.5 - Prob. 43ECh. A.5 - Prob. 44ECh. A.5 - Prob. 45ECh. A.5 - Prob. 46ECh. A.5 - Prob. 47ECh. A.5 - Prob. 48ECh. A.5 - Prob. 49ECh. A.5 - Prob. 50ECh. A.5 - Prob. 51ECh. A.5 - Prob. 52ECh. A.5 - Prob. 53ECh. A.5 - Prob. 54ECh. A.5 - Prob. 55ECh. A.5 - Prob. 56ECh. A.5 - Prob. 57ECh. A.5 - Prob. 58ECh. A.5 - Prob. 59ECh. A.5 - Prob. 60ECh. A.5 - Prob. 61ECh. A.5 - Prob. 62ECh. A.5 - Prob. 63ECh. A.5 - Prob. 64ECh. A.5 - Prob. 65ECh. A.5 - Prob. 66ECh. A.5 - Prob. 67ECh. A.5 - Prob. 68ECh. A.5 - Prob. 69ECh. A.5 - Prob. 70ECh. A.5 - Prob. 71ECh. A.5 - Prob. 72ECh. A.5 - Prob. 73ECh. A.5 - Prob. 74ECh. A.5 - Prob. 75ECh. A.5 - Prob. 76ECh. A.5 - Prob. 77ECh. A.5 - Prob. 78ECh. A.5 - Prob. 79ECh. A.5 - Prob. 80ECh. A.5 - Prob. 81ECh. A.5 - Prob. 82ECh. A.5 - Prob. 83ECh. A.5 - Prob. 84ECh. A.5 - Prob. 85ECh. A.5 - Prob. 86ECh. A.5 - Prob. 87ECh. A.5 - Prob. 88ECh. A.5 - Prob. 89ECh. A.5 - Prob. 90ECh. A.5 - Prob. 91ECh. A.5 - Prob. 92ECh. A.5 - Prob. 93ECh. A.5 - Prob. 94ECh. A.5 - Prob. 95ECh. A.5 - Prob. 96ECh. A.5 - Prob. 97ECh. A.5 - Prob. 98ECh. A.5 - Prob. 99ECh. A.5 - Prob. 100ECh. A.6 - Prob. 1ECh. A.6 - Prob. 2ECh. A.6 - Prob. 3ECh. A.6 - Prob. 4ECh. A.6 - Prob. 5ECh. A.6 - Prob. 6ECh. A.6 - Prob. 7ECh. A.6 - Prob. 8ECh. A.6 - Prob. 9ECh. A.6 - Prob. 10ECh. A.6 - Prob. 11ECh. A.6 - Prob. 12ECh. A.6 - Prob. 13ECh. A.6 - Prob. 14ECh. A.6 - Prob. 15ECh. A.6 - Prob. 16ECh. A.6 - Prob. 17ECh. A.6 - Prob. 18ECh. A.6 - Prob. 19ECh. A.6 - Prob. 20ECh. A.6 - Prob. 21ECh. A.6 - Prob. 22ECh. A.6 - Prob. 23ECh. A.6 - Prob. 24ECh. A.6 - Prob. 25ECh. A.6 - Prob. 26ECh. A.6 - Prob. 27ECh. A.6 - Prob. 28ECh. A.6 - Prob. 29ECh. A.6 - Prob. 30ECh. A.6 - Prob. 31ECh. A.6 - Prob. 32ECh. A.6 - Prob. 33ECh. A.6 - Prob. 34ECh. A.6 - Prob. 35ECh. A.6 - Prob. 36ECh. A.6 - Prob. 37ECh. A.6 - Prob. 38ECh. A.6 - Prob. 39ECh. A.6 - Prob. 40ECh. A.6 - Prob. 41ECh. A.6 - Prob. 42ECh. A.6 - Prob. 43ECh. A.6 - Prob. 44ECh. A.6 - Prob. 45ECh. A.6 - Prob. 46ECh. A.6 - Prob. 47ECh. A.6 - Prob. 48ECh. A.6 - Prob. 49ECh. A.6 - Prob. 50ECh. A.6 - Prob. 51ECh. A.6 - Prob. 52ECh. A.6 - Prob. 53ECh. A.6 - Prob. 54ECh. A.6 - Prob. 55ECh. A.6 - Prob. 56ECh. A.6 - Prob. 57ECh. A.6 - Prob. 58ECh. A.6 - Prob. 59ECh. A.6 - Prob. 60ECh. A.6 - Prob. 61ECh. A.6 - Prob. 62ECh. A.6 - Prob. 63ECh. A.6 - Prob. 64ECh. A.6 - Prob. 65ECh. A.6 - Prob. 66ECh. A.6 - Prob. 67ECh. A.6 - Prob. 68ECh. A.6 - Prob. 69ECh. A.6 - Prob. 70ECh. A.6 - Prob. 71ECh. A.6 - Prob. 72ECh. A.6 - Prob. 73ECh. A.6 - Prob. 74ECh. A.6 - Prob. 75ECh. A.6 - Prob. 76ECh. A.6 - Prob. 77ECh. A.6 - Prob. 78ECh. A.6 - Prob. 79ECh. A.6 - Prob. 80ECh. A.6 - Prob. 81ECh. A.6 - Prob. 82ECh. A.6 - Prob. 83ECh. A.6 - Prob. 84ECh. A.6 - Prob. 85ECh. A.6 - Prob. 86ECh. A.6 - Prob. 87ECh. A.6 - Prob. 88ECh. A.6 - Prob. 89ECh. A.6 - Prob. 90ECh. A.6 - Prob. 91ECh. A.6 - Prob. 92ECh. A.6 - Prob. 93ECh. A.6 - Prob. 94ECh. A.6 - Prob. 95ECh. A.6 - Prob. 96ECh. A.6 - Prob. 97ECh. A.6 - Prob. 98ECh. A.6 - Prob. 99ECh. A.6 - Prob. 100ECh. A.6 - Prob. 101ECh. A.6 - Prob. 102ECh. A.6 - Prob. 103ECh. A.6 - Prob. 104ECh. A.6 - Prob. 105ECh. A.6 - Prob. 106ECh. A.6 - Prob. 107ECh. A.6 - Prob. 108ECh. A.6 - Prob. 109ECh. A.6 - Prob. 110ECh. A.6 - Prob. 111ECh. A.6 - Prob. 112ECh. A.6 - Prob. 113ECh. A.6 - Prob. 114ECh. A.6 - Prob. 115ECh. A.7 - Prob. 1ECh. A.7 - Prob. 2ECh. A.7 - Prob. 3ECh. A.7 - Prob. 4ECh. A.7 - Prob. 5ECh. A.7 - Prob. 6ECh. A.7 - Prob. 7ECh. A.7 - Prob. 8ECh. A.7 - Prob. 9ECh. A.7 - Prob. 10ECh. A.7 - Prob. 11ECh. A.7 - Prob. 12ECh. A.7 - Prob. 13ECh. A.7 - Prob. 14ECh. A.7 - Prob. 15ECh. A.7 - Prob. 16ECh. A.7 - Prob. 17ECh. A.7 - Prob. 18ECh. A.7 - Prob. 19ECh. A.7 - Prob. 20ECh. A.7 - Prob. 21ECh. A.7 - Prob. 22ECh. A.7 - Prob. 23ECh. A.7 - Prob. 24ECh. A.7 - Prob. 25ECh. A.7 - Prob. 26ECh. A.7 - Prob. 27ECh. A.7 - Prob. 28ECh. A.7 - Prob. 29ECh. A.7 - Prob. 30ECh. A.7 - Prob. 31ECh. A.7 - Prob. 32ECh. A.7 - Prob. 33ECh. A.7 - Prob. 34ECh. A.7 - Prob. 35ECh. A.7 - Prob. 36ECh. A.7 - Prob. 37ECh. A.7 - Prob. 38ECh. A.7 - Prob. 39ECh. A.7 - Prob. 40ECh. A.7 - Prob. 41ECh. A.7 - Prob. 42ECh. A.7 - Prob. 43ECh. A.7 - Prob. 44ECh. A.7 - Prob. 45ECh. A.7 - Prob. 46ECh. A.7 - Prob. 47ECh. A.7 - Prob. 48ECh. A.7 - Prob. 49ECh. A.7 - Prob. 50ECh. A.7 - Prob. 51ECh. A.7 - Prob. 52ECh. A.7 - Prob. 53ECh. A.7 - Prob. 54ECh. A.7 - Prob. 55ECh. A.7 - Prob. 56ECh. A.7 - Prob. 57ECh. A.7 - Prob. 58ECh. A.7 - Prob. 59ECh. A.7 - Prob. 60ECh. A.7 - Prob. 61ECh. A.7 - Prob. 62E
Knowledge Booster
Background pattern image
Calculus
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, calculus and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Calculus: Early Transcendentals
Calculus
ISBN:9781285741550
Author:James Stewart
Publisher:Cengage Learning
Text book image
Thomas' Calculus (14th Edition)
Calculus
ISBN:9780134438986
Author:Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:PEARSON
Text book image
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:9780134763644
Author:William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:PEARSON
Text book image
Calculus: Early Transcendentals
Calculus
ISBN:9781319050740
Author:Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:W. H. Freeman
Text book image
Precalculus
Calculus
ISBN:9780135189405
Author:Michael Sullivan
Publisher:PEARSON
Text book image
Calculus: Early Transcendental Functions
Calculus
ISBN:9781337552516
Author:Ron Larson, Bruce H. Edwards
Publisher:Cengage Learning
SEE MORE TEXTBOOKS
Interpreting Graphs of Quadratic Equations (GMAT/GRE/CAT/Bank PO/SSC CGL) | Don't Memorise; Author: Don't Memorise;https://www.youtube.com/watch?v=BHgewRcuoRM;License: Standard YouTube License, CC-BY
Solve a Trig Equation in Quadratic Form Using the Quadratic Formula (Cosine, 4 Solutions); Author: Mathispower4u;https://www.youtube.com/watch?v=N6jw_i74AVQ;License: Standard YouTube License, CC-BY