Вправи: 742

742. Скоротіть дріб:

1) 4a2- 92a2- 9a-18 = 2a-3(2a+3)2a-6(a+1,5) = 2a-3(2a+3)a-6(2a+3) = 2a-3a-6;

2) 2b2- 7b+34b2- 4b+1 = 2b-3(b-0,5)(2b-1)2 = b-3(2b-1)(2b-1)2 = b-32b-1;

3) c2- 5c-6c2- 8c+12 = c-6(c+1)c-6(c-2) = c+1c-2;

4) m3- 1m2+ 9m-10 = m-1(m2+ m+1)m+10(m-1) = m2+ m+1m+10;

5) x2- 1632-4x- x2 = x-4(x+4)-x-4(x+8) = –x+4x+8;

6) 4n2- 9n+22+9n-5n2 = 4n-2(n- 14)-5n-2(n+ 15) = n-2(4n-1)-n-2(5n+1) = –4n-15n+1 = 1-4n5n+1.