Решить примеры: 1)(3c-2d)*(d-c) 2)(a+b)*(3a-b+2) 3)(x^2+1)*(4-x^2) 4)(5-x)(5+x) 5)(5-x)(5-x)

1) (3c-2d)(d-c)=3cd-3c²-2d²-2cd=cd-3c²-2d²
2) (a+b)(3a-b+3)=3a²-ab+3a+3ab+3b=3a²+3a+2ab+3b
3) (x²+1)(4-x²)=4x²+4-x²=3x²+4
4) (5-x)(5+x)=25-x²
5) (5-x)(5-x)=25-5x-5x+x=-9x+25

1) 3cd-3c^2-2d^2+2dc
2)3a^2-ab+2b+3ab-b^2+2b
3)4x^2 -x^4-4-x^2
4)25-x^2
5)25-5x-5x+x^2