Your formatting is a bit odd, but it looks like the student went from 4x = 28 to x = 112, which is incorrect. If I'm reading that right, then the error is in that last step. The answer should be x = 7. You divide both sides by 4 to go from 4x = 28 to x = 7. The student or teacher must have multiplied 28 by 4 on accident.
note: replace x with 7 and we can check the answer
4*(x+3) = 40
4*(7+3) = 40
4*10 = 40
40 = 40
We get a true equation, so the answer is confirmed
