Question 231285
You need to isolate for y in that equation.

25x-5y=15

Add 5y to both sides:

25x-5y+5y=15+5y
25x=15+5y

Subtract 15 from both sides

25x-15=15+5y-15
25x-15=5y

Divide both sides by 5:

25x/5-15/5=5y/5
5x-3=y

Or rearrange to have in y=mx+b form:

y=5x-3