Isolate the y. Note the equal sign. What you do to one side, you do to the other.
First, subtract 9x from both sides
9x (-9x) - y = 45 (-9x)
-y = -9x + 45
Next, divide - 1 from both sides to isolate the y.
(-y)/-1 = (-9x + 45)/-1
y = 9x - 45
y = 9x - 45 is your answer
hope this helps
