To solve, you would need -
C. Subtraction property of equality
Isolate the x. Subtract 5x from both sides
8x (-5x) = 5x (-5x) - 15
3x = -15
Next, to isolate the x, you would need
E. Division property of equality
Divide 3 from both sides
3x/3 = -15/3
x = -5
x = -5 is your answer
hope this helps