Hello!! Let's solve this!
-2(3x+9)= 24
Distribute the 2 using the distributive property, which states: a(b + c) = ab + ac
-2(3x+9)= 24
-2(3x) + (-2)(9) = 24
Simplify it
-6x - 18 = 24
Add 18 on both sides
-6x - 18 + 18 = 24 + 18
-6x = 42
Divide -6 on both sides
-6x/-6 = 42/-6
x = -7
Your answer is x = -7.
Hope I helped! If you have any other questions or would like further explanation just let me know!! :)