6 (10-х) (3 х+4) = 0

2 (5 х-7) (1+х) = 0

(3 х+18) (2-х) = 0

(6-х) (5 х+40) = 0

6 (10-х) (3 х+4) = 0

10-x=0 или 3x+4=0

x=10 3x=-4

x=-4/3

2) 2 (5 х-7) (1+х) = 0

(5x-7) = 0 или (1+x) = 0

5x=7 x=-1

x=7/5

3) (3 х+18) (2-х) = 0

x=-6; x=2;

(6-х) (5 х+40) = 0

6-x=0 или 5x+40=0

x=6 5x=-40

x=-8