Question

the sum of a number and 9 is multiplied by -2 and the answer is 8 find the number. I know the answer is -5 i need a expression, or equation. Any of them both HELP

Answer 1

-2(X+9)=8
-2X-18=8
-2X-18+18=8+18
-2X=26
-2X/-2=26/-2
X=-13

-2(X+9)=8
(-2(X+9))/-2=8/-2
X+9=-4
X+9-9=-4-9
X=-13
I'm not sure if this helps. This is what I get. Not sure about -5.