9q+24=3(3q-4)

Let's look at this again

9q+24=3(3q-4)    so we have

9q+24= 9q - 12    

Note that this doesn't have a solution...to see why, note that if I add 24 to 9q  ...  it can't possibly be equal to the same thing as subtracting 12 from it.....!!!!

q= -36 because 9q and 9q eliminate themselves so you are left with q. Then subtract 24 from both sides to get q= -36.