Chapter ISG, Problem 2.1.1.1P

a.

To determine

To write an equation

Answer to Problem 2.1.1.1P

  $x^2-x-20=0$

Explanation of Solution

Given information:

A number is increased by 7 is equal to 13 less than the square of the number

Calculation:

Let the number be x,

According to question,

  $x+7=x^2-13$

Shifting all terms to right hand side,

  $x^2-13-x-7=0$

On solving,

  $x^2-x-20=0$

Hence, the equation is $x^2-x-20=0$

b.

To determine

To write an equation

Answer to Problem 2.1.1.1P

  $3x+9=3(x+3)$

Explanation of Solution

Given information:

The sum of 3 times a number and 9 equals 3 times the sum of the number and 3

Calculation:

Let the number be x,

According to question,

  $3x+9=3(x+3)$

Hence, this is the equation

c.

To determine

To write an equation

Answer to Problem 2.1.1.1P

  $\frac{2x}{7}=5$

Explanation of Solution

Given information:

The quotient of 7 and twice a number equals 5

Calculation:

Let the number be x,

According to question,

  $\frac{2x}{7}=5$

Hence, this is the equation