Answer:
a) Equation Y=0.50(x-50)
b) Marlena sold 121 books
Explanation:
Each book Marlena sells above 50 she earns $0.50 of bonus. If she sells less, no bonus is earned, so if x is the number of books sold and y is the amount of the bonus earned:
y = 0.50 ( x - 50 ) x > 50
If we know she earned a bonus of y = 35.50, we must calculate x from the above equation:
35.50 = 0.50 ( x - 50 )
x - 50 = 35.50 / 0.50 = 71
x = 50 + 71 = 121 books
Marlena sold 121 books