5x + 17 = 3x + 7
isolate the x, subtract 3x from both sides and 17 from both sides
5x (-3x) + 17 (-17) = 3x (-3x) + 7 (-17)
5x - 3x = 7 - 17
2x = -10
Isolate the x, divide 2 from both sides
2x/2 = -10/2
x = -10/2
x = -5
D. x = -5 is your answer
hope this helps