Solve : y (y-9) = - 18

We probably want to get this into standard form (ax^2 + bc + c = 0). Our first step is to distribute the y into the parentheses:

y^2 - 9y = - 18

Now add 18 to both sides:

y^2 - 9y + 18 = 0

Factor. In order to do this, find two factors of 18 that add to - 9. These would be - 6 and - 3. We can now rewrite the equation as binomials:

(x - 6) (x - 3) = 0

Solve both separately:

x - 6 = 0

x = 6

x - 3 = 0

x = 3

Your two solutions are x = 6 and x = 3.