Question

Christine is a software saleswoman. Let y represent her total pay (in dollars). Let x represent the number of copies of Math is Fun she sells. Suppose that x and y are related by the equation 70x + 1700= y.Answer the questions below. Note that a change can be an increase or a decrease. For an increase, use a positive number. For a decrease, use a negative number. What is the change in Christine’s total pay for each copy of Math is Fun she sells? What is Christine’s total pay if she doesn’t sell any copies of Math is Fun?

Answer 1

From the information given, the equation relating her total pay (in dollars), y to the number of copies of Math is Fun she sells, x is expressed as

y = 70x + 1700

This is a linear equation. The slope intercept form of a linear equation is expressed as

y = mx + b

where

m = slope or rate of change

b = y intercept of the value of y when x = 0

By comparing both equations,

m = 70

b = 1700

a) Thus, the change in Christine’s total pay for each copy of Math is Fun she sells 70 dollars per copy

b) Christine’s total pay if she doesn’t sell any copies of Math is Fun is the value of y when x = 0. thus,

Christine’s total pay if she doesn’t sell any copies of Math is Fun = $1700