a) x(5b + 3) - 7(5b + 3) = (5b + 3)(x - 7)
б) 4m + 4x - am - ax = 4(m + x) - a(m + x) = (m + x)(4 - a)
в) ab - 3a - b² + 3b = a(b - 3) - b(b - 3) = (b - 3)(a - b)
г) cx - cy + 2y - 2x - ay + ax = c(x - y) - 2(x - y) + a(x - y) = (x - y)(c - 2 + a)
Ответ: a) (5b + 3)(x - 7); б) (m + x)(4 - a); в) (b - 3)(a - b); г) (x - y)(c - 2 + a)