Решите.
(a-1)(4a+5)=?
(2a-3)(x-6)=?
(M'2+n)(2m-4n'2)=?
2x(x+y)-(x+y)(2x-y)=?
Срочно

=4a^2+5a-4a-5=4a^2+a-5

=2ax-12a-3x+18

=2m^3-4m^2n^2+2mn-4n^3

=2x^2+2xy-(2x^2-xy+2xy-y^2)= xy + y^2