you are correct, its 3x + 4 = 2x
you have to get the variable on 1 side and the number on the other side so subtract 3x from both sides
4 = -1x divide each side by a -1
-4 = x is your answer and the one value
check: (it is always good to check your work) 3(-4) = -12 + 4 = -8
-8 is twiice -4 which means the answer is correct.