Способ группировки:

1) 16ab^2 - 5b^2c - 10c^3 + 32ac2;

2) - 28ac + 35c^2 - 10cx + 8ax;

3) 6mnk + 15m^2k - 14n^3k - 35mn^2;

4) - 24bx - 15c^2 + 40bc + 9cx.

1) 16ab^2 - 5b^2c - 10c^3 + 32ac2=16a (b ²+2c²) - 5c (b²+2c²) = (b²+2c²) (16a-5c)

2) - 28ac + 35c^2 - 10cx + 8ax=-7c (4a-5c) + 2x (4a-5c) = (4a-5c) (2x-7c)

3) 6mnk + 15m^2k - 14n^3k - 35mn^2=3mk (2n+5m) - 7n ² (2n+5m) =

= (2n+5m) (3mk-7n ²)

4) - 24bx - 15c^2 + 40bc + 9cx=-3x (8b-3c) + 5c (8b-3c) = (8b-3c) (5c-3x)