Hi there!
To solve this problem, we need to simplify the values inside the parenthesis first.
0.5 (31 - 4 - x - 3x) = 9
0.5 (27 - 4x) = 9
Now, we distribute the 0.5 into the parenthesis:
0.5*27 - 0.5*4x = 9
13.5 - 2x = 9
Now, we subtract 13.5 from both sides:
-2x = 9 - 13.5
-2x = -4.5
2x = 4.5
And solve for x.
x = 2.25
Hope this helps!