Question

Can someone help me on this. I've tried over and over trying to figure out which step is incorrect but no luck. Help me out; write explanation and evidence please

Answer 1

If we can see in step C, we have that:

$(x+2)^2=x^2+2\cdot2x+2^2=x^2+4x+4$

Then, in step C, we have that:

$5x=x^2+4x+4$

The explanation is that the square of (x+2)^2 = x^2 + 4x + 4, and not x^2 + 4.