Вправи: 42

42. Скоротіть дріб:

1) a(x-y)5(y-x) = -a(y-x)5(y-x) = –a5;3) 7y-14y2- 4 = 7(y-2)y-2(y+2) = 7y+2;

2) 3a-9b15b-5a = 3(a-3b)-5(a-3b) = –35;

4) m2- 9m2- 6m+9 = m-3(m+3)(m-3)2 = m+3m-3;

5) p2- 1p3- p2 = p-1(p+1)p2(p-1) = p+1p2;

6) x2+ 10x+25mx+5m = (x+5)2m(x+5) = x+5m.