7ax - ay + 7bx - by = 7x(a + b) - y(a + b) = (7x - y)(a + b)
ИЛИ
7ax - ay + 7bx - by= a (7x - y) + b (7x - y) = (a + b)(7x - y)
7ax - ay + 7bx - by = 7x(a + b) - y(a + b) = (7x - y)(a + b)
ИЛИ
7ax - ay + 7bx - by= a (7x - y) + b (7x - y) = (a + b)(7x - y)