Вправи: 122

122. Спростіть вираз:

1) (9m2- 3mn+ n2)\3m+n3m-n – (9m2+ 3mn+ n2)\3m-n3m+n = 3m+n9m2- 3mn+ n2- (3m-n)(9m2+ 3mn+ n2)3m-n(3m+n) = (3m)3+ n3- (3m)3- n3)3m-n(3m+n) = 27m3+ n3- 27m3+ n33m-n(3m+n) = 27m3+ n3- 27m3+ n33m-n(3m+n) = 2n39m2- n2;

2) 1\8b3+1 – 2b-1\2b+1 4b2- 2b+1 – 2b4b2-2b+12b+1 = 8b3+ 1-2b-12b+1- 2b(4b2- 2b+1)2b+1(4b2- 2b+1) = 2-2b8b3- 1.