Question

A pencil at a stationery store costs $1, and a pen costs $1.50. Shawn spent $12 at the store. He bought a total of 9 items. Which system of equations can be used to find the number of pencils (x) and pens (y) he bought?

1.5x + y = 12
x = 9y
x + 1.5y = 12
x + y = 9
x + 9y = 12
x = 1.5y
9x + y = 12
x = 1.5y

Answer 1

If 1 pencil costs $1, how much do x pencils cost?

Answer 2

If 1 pencil costs $1, then 2 pencils cost $1 * 2.
10 pencils cost $1 * 10.
x pencils cost $1 * x = 1x = x

Now dot he same for pens.
If 1 pen costs $1.50, what do y pens cost?