Вправи: 43

43. Скоротіть дріб:

1) (3a+3b)2a+b = (3(a+b))2a+b = 9(a+b)2a+b = 9(a+b)1 = 9a + 9b;

2) (6x-18y)2x2- 9y2 = (6(x-3y))2x-3y(x+3y) = 36x-3y(x-3y)x-3yx+3y = 36(x-3y)x+3y = 36x-108yx+3y;

3) xy+x-5y-54y+4 = xy+1- 5(y+1)4(y+1) = y+1(x-5)4(y+1) = x-54;

4) a2- ab+2b-2aa2- 4a+4 = aa-b- 2(a-b)(a-2)2 = a-b(a-2)(a-2)2 = a-ba-2.