Выполните умножение:

Решите задачу:

$(a + b)(x - y) = ax - ay + bx - by \\ (a - b)(x + y) = ax + ay - bx - by \\ (m - n)(p + q) = mp + mq - np - nq \\ (a + b)(a + 2) = {a}^{2} + 2a + ab + 2b \\ (y + 2)(y - 3) = {y}^{2} - 3y + 2y - 6 = {y}^{2} + y - 6$
$(a + 1)(a - 3) = {a}^{2} - 3a + a - 3 = {a}^{2} - 2a - 3 \\ (p + x)(q - y) = pq - py + xq- xy \\ (a + b)(c - d) = ac - ad + bc - bd \\ (x + 1)(x - 1) = {x}^{2} - x + x - 1 = {x}^{2} - 1$