Question

(2а+3)(а-3)-2а(4-а)
(1-х)(х-1)+(х-1)
(а+в)(а-2в)+(2в-а)(2в+а)

Answer 1

1)(2a+3)(a-3)-2a(4-a)=2a²-6a+3a-9-8a+2a²=4a²-11a-9
2)(1-x)(x-1)+(x-1)=x-1-x²-x=1-x²+x-1=-x²-x
3)(a+b)(a-2b)+(2b-a)(2b+a)=a²-2ab+ab-2b²+4b²-a²=-ab-2b²