Question

преобразуйте в многочлен

1) (a+b-c+d)(a+b+c-d)
2) (a-b-c+d)(a-b+c-d)

Answer 1

1) (a+b)^2-(-c+d)^2=a^2+2ab+b^2-(d^2-2cd+c^2)=a^2+2ab+b^2-d^2+2cd-c^2

2) (a-b)^2-(-c+d)^2=a^2-2ab+b^2-(d^2-2cd+c^2)=a^2-2ab+b^2-d^2+2cd-c^2