Question

Molly and Maddie are clothes shopping. Molly has $100.00 and a coupon for a $5.00 discount at a clothing store where each shirt costs $15.00. Molly thinks that she can buy 8 shirts, but Maddie says that Molly can buy 7 shirts. The equations they used to model the problem are listed below.

Solve each equation algebraically, justify your steps, and determine who is correct and why.

Molly's equation
15x + 10 = 100

Maddie's equation
15x - 10 = 100

Answer 1

Explanation:

let us start with

Molly's equation

15x + 10 = 100

solving for x we have

15x=100-10

15x=90

x=90/15

x=6

Maddie's equation

15x - 10 = 100

solving for x we have

15x=100+10

15x=120

x=120/15

x=8

well, from the solution niether of them is correct