Решите уровнение 69-(13-у)=-у 31-t=-(t-9)
69 - (169 - 26 + y2) = -y2 69 - 169 + 26y - y2 = -y2 69 - 169 + 26y = 0 -100 + 26y = 0 26y = 100 y = 50/13