4) 3s-2q 2q-3s

4) a = 3s - 2q, b = 2q - 3s

a + b = (3s - 2q) + (2q - 3s) = 3s - 2q + 2q - 3s = 0

a - b = (3s - 2q) - (2q - 3s) = 3s - 2q - 2q + 3s = 6s - 4q

Ответ: a + b = 0, a - b = 6s - 4q