Answer: x=3
Step-by-step explanation: you can rewrite -(3x-9) as -1*(3x-9). as the negative sign is the same as -1. Now if you distribute you get -3x+9. then set this equation equal to zero and subtract 9 from both sides and you'll get -3x=-9. next divide both sides by -3 and you should get the answer x=3.
-(3x-9)
-1*(3x-9)
-3x-9=0
-3x=-9
x=3