Ricardo spent half of his allowance on school supplies. Then he bought a snack for $5.25. When he arrived home he had $22.50 left.

Question

write and solve the equation to find the amount of Ricardo's allowance a

Answer 1

First, we set up the terms of the equation

a= allowance

Richard spent 1/2 of his allowance, so we can put 1/2a to represent that.

So far:

a- 1/2a

Then:

He bought a snack for 5.25.

a - 1/2a - 5.25

Now: a - 1/2a - 5.25 = 22.50

1. 1/2a - 5.25 = 22.50 (adding variable "a" terms together)
2. 1/2a= 27.75 (adding 5.25 to 22.50)
3. a/0.5= 27.75/0.5 (divide both sides by 1/2, or 0.5)

a= 55.5

$55.50 is Richard's allowance

Answer 2

Allowance = A

he spent half on school supplies, leaving half left, A/2

then he spent $5.25 on snacks

A/2 - 5.25 = 22.50

add 5.25 to both sides:

A/2 = 22.50 + 5.25 = 27.75

A/2 = 27.75

multiply both sides by 2

A = 2(27.75) = $55.50

he spent half of $55.50 on school supplies leaving 55.50/2 = $27.75

then he spent $5.25 leaving 27.75-5.25 = $22.50