Вправи: 530

530. Скоротіть дріб:

1) 4a+45a2- 5 = 4(a+ 5)(a- 5)(a+ 5) = 4a- 5;

2) 28- 22a6a-21 = 4•7- 22a3(2-7a) = 27-22a3((2)2-(7 )2) = 2(7 - 2a)3(2a + 7)(2a - 7) = 22(2a - 7)3(2a + 7)(2a - 7) = –23(2a + 7);

3) a+4ab+4ba-4b = (a)2+2•2ab +(2b)2(2)2-(2b)2 = (a +2b)2(a -2b)(a +2b) = a+ 2ba- 2b;

4) x2- 6yx2+ 6y- x24y = x2- (6y)2x2- 2x6y+(6y)2 = (x- 6y)(x+ 6y)(x- 6y)2 = x+6y x- 6y;

5) a+ ba3+ b3 = a+b (a)3+(b)3 = a+b(a + b)(a- ab + b) = 1a-ab + b;

6) mm-27m- 3 = (m)3-33 m- 3 = (m -3)(m+3m+9)m- 3 = m + 3m + 9.