Question

Tim was asked to solve the equation kx = my - mx for x. His solution is shown below.

Start : kx = my - mx

Step 1: kx+mx= my

Step 2: x(k+m) = my

Step 3: x= my/k+m / sign is a fraction bar

In which step did Tim make his FIRST mistake when solving the equation?

A. Step 1
B. Step 2
C. Step 3
D. Tim did not make a mistake.

I think it is 'A'?