Ok, let's take this step by step.
-10 + 9y = 12 - 24
First, we will simplify both sides of the equation. In this case, the left side needs to be simplified.
-10 + 9y = -12
Now, we need to begin isolating the variable by adding 10 to both sides.
9y = -2
Now, we need to divide each side by 9 to isolate y.
y = -2/9
To check, we can plug this into our original simplified equation (-10 + 9y = -12)
-10 + 9(-2/9) = -12
-10 + (-2) = -12
-10 - 2 = -12
-12 = -12
Since -12=-12, y=-2/9. :)