Y = 15x

y = 25 + 12.5x

Substitute y = 15x to the equation y = 25 + 12.5x:

15x = 25 + 12.5x subtract 12.5x from both sides

2.5x = 25 divide both sides by 2.5

x = 10

Substitute the value of x to the equation y = 15x:

y = (15) (10)

y = 150

Answer: x = 10 and y = 150