Đáp án:

a, $$a(x-y)+5(y-x)=a(x-y)-5(x-y)=(a-5)(x-y)$$

b, $$2x(3x-y)-5(y-3x)=(3x-y)(2x+5)$$

c, $$8x-10y=2(4x-5y)$$

d, $$x^2yz^3-4xyz+7xyz^3=xyz(xz-4+7z)$$

e, $$2a(a+5b)-(a+5b)=(a+5b)(2a-1)$$

f, $$4x(7x-1)-5(7x-1)=(7x-1)(4x-5)$$

g, $$9x^2(5-3x)+6x(3x-5)=3x(3x-5)(2-3x)$$

h, $$6a^2b(9-3a)-9ab(4-3a)+12ab^2(3a-4)$$

$$=3ab[2a(9-3a)-3(4-3a)+4b(3a-4)]$$

$$=3ab(18a-6a^2-12+9a+12ab-16b)$$

$$=3ab(27a-6a^2-12+12ab-16b)$$