Question

2)х^4 -(x^2-1)(x^2+1)=1 доказать равенство
3)x^4-(x^2-7)(x^2+7)=49
4)(x-3)(x+7)-(x+5)(x-1)=-16

Answer 1

2)x^4-x^4+1=1
1=1
3)x^4-x^4+49=49
49=49
4)x^2+7x-3x-21-(x^2-x+5x-5)=-16
-16=-16

Answer 2

со