Вправи: 537

537. Спростіть вираз:

1) a- 3a+ 1 – a- 4a = aa- 3- (a- 4)(a+ 1)a(a+ 1) = a-3a- (a+ a- 4a- 4)a(a+ 1) = a-3a- a+4a- a+ 4a(a+ 1) = 4a+ a;

2) a+ 1a- ab – b+ 1ab- b = a+ 1(a)2- ab – b+ 1ab- (b)2 = a+ 1\ba(a- b) – b+ 1\ab(a- b) = ab+ b- ab- aab(a- b) = -(a- b)ab(a- b) = –1ab;

3) xy-2y : x3y-6 = x • 3(y- 2)yy- 2 • x = 3y;

4) c- 5c : c-253с = c- 5 • 3cc • (c-25) = c- 5 • 3(c)2cc- 5(c+ 5) = 3cc+ 5.