Answer:
x = 15 (D)
Explanation:
First, we distribute the -1/2:
-1/2 x x = -1/2x
-1/2 x 5 = -2.5
Now we have -1/2x + (-2.5) = -10
Move the variables to one side and the regular numbers on the other (in other words, subtracting both sides by -2.5:
-1/2x = -10 + 2.5
-1/2x = -7.5
x = -7.5/(-1/2)
x = 15 (D)