Разложите на множители 1) 2y(5+a)-3x(5+a)
2) 5(c-d)-9x(d-c)
3) 8(a-3)+(a-3)^2
4)(x-4)(7y+30-(x-4)(5y-9)

1) 2y(5 + a) - 3x(5 + a) = (2y - 3x)(5 + a);

2) 5(c - d) - 9x(d - c) = 5(c - d) + 9x(c - d) = (5 + 9x)(c - d);

3) 8(a - 3) + (a - 3)² = (a - 3)(8 + a - 3) = (a - 3)(a + 5);

4) (x - 4)(7y + 30) - (x - 4)(5y - 9) = (x - 4)(7y + 30 - 5y + 9) = (x - 4)(2y + 39).