Question

(y+5)(y-4)-(y-5)(y+5)​

Answer 1

Ответ:

$(y + 5)(y - 4) - (y - 5)(y + 5) = (y + 5)((y - 4) - (y - 5)) = (y + 5)(y - 4 - y + 5) = (y + 5) \times 1 = y + 5$