Question

PLEASE AID ME IN MY DESPAIR!
The monthly cost to run the electrical system in a company's office is $355, plus $18 per hour. In another of it's offices, the monthly cost is $514, plus $15 per hour.

A) Write an equation that could be solved to determine after how many hours the two offices have the same electrical costs.

B) Solve your equation.

C) What is that cost?

D) How could you check your answer?

Answer 1

A) $355 + $18x = $514 + $15x

B) $355 + $18x = $514 + $15x
355 -355 + 18x = 514 -355 + 15x
18x = 159 + 15x
18x-15x=159+15x-15x
3x = 159
3x/3=159/3
x = 53

C) $355 + $18(53) = $1309
$514 + $15(53)= $1309

D) You can check your answer by taking what x equals and plugging back into the original formula of $355+$18x=$514+$15x. Then solve making sure the left side equals the right side.

$355+$18x=$514+$15x
$355 + $18(53)=$514 + $15(53)
$1309 = $1309