Question

Алгебра
1) (3-b)(3+b)-2b(b-3)
2)-5y(y+3)+(y-4)^2
3) 3(x-9)^2-3x^2

Answer 1

Пишу сразу ответ
1) (3-b)×(3+b)-2b×(-(3-b))=(3-b)×(3+b)+2b×(3-b)=(3-b)×(3+b+2b)=(3-b)×(3+3b)=(3-b)×3(1+b)=3(3-b)×(1+b)
2) -5y²-15y+2y-8=-5y²-13y-8
3) 6(x-9)-6x=6x-54-6x=-54