Respuesta :
39 * 5 is indeed 195. For the second part, the error is that your friend subtracted 28 from the left side (375) instead of adding it (inverse operations to get rid of the -28). What you need to do is add 28 to each side to get x alone:
375 = x - 28
403 = x
Does that make sense?
375 = x - 28
403 = x
Does that make sense?