Вправи: 167

167. Спростіть вираз:

1) 25-5a+5b-ab25+5a-5b-ab • ab-5a-5b+25ab+5a+5b+25 = 55-a+ b5- a(ab-5- 5b-5)55+a- b5+a(ab+5+ 5b+5) = 5-a5+bb-5(a-5)5+a5-bb+5(a+5) = -a-5b-5(a-5)-a+5b-5(a+5) = (a-5)2(a+5)2;

2) a2- 2ab+ b2a2- ab-4a+4b2 : a2- ab+4a-4b2a2- 16 = (a-b)2(a-4)(a+4)aa-b- 4a-b(aa-b+ 4a-b) = (a-b)2(a-4)(a+4)a-ba-4a-b(a+4) = 1.