2x(x-3)-3x(x+5) 3(y+5)^2-3y^2 (a+7)(a-1)+(a-3)^2

Question

2x(x-3)-3x(x+5)
3(y+5)^2-3y^2
(a+7)(a-1)+(a-3)^2

Comments

а задание какое

Answer 1

=2x²-6x-3x²-15x=-x²-21x
=3y²+30y+75-3y²=30y+75
=a²-a+7a-7+a²-6a+9=2a²+2