Question

Помогите ПЛИЗ со всеми четырьмя номерами

Answer 1

1)
$c(x + y) + 4x + 4y = c(x + y) + 4(x + y) = (x + y)(c + 4)$
2)
$6a - 6c + ay - cy = 6(a - c) + y(a - c) = (a - c)(6 + y)$
3)
$xa - xb - ya + yb = x(a - b) - y(a - b) = (a - b)(x - y)$
4)
$7 {y}^{3} + 7 {y}^{2} - y - 1 = 7 {y}^{2} (y + 1) - (y + 1 ) = (y + 1)(7 {y}^{2} - 1) = (y + 1)(y sqrt{7} - 1)(y sqrt{7} + 1)$