Выражение (3х^2-2х)+(-х^2+3х) 2) (4с^2-+8cd) 3)(12m^2-7n--10n+14m^2) 4)(3n^3 -2mn++3n^3)

1) (3·x²-2·x)+(-х²+3·x)=3·x²-2·x-x²+3·x=3·x²-х²+3·x-2·x=2·x²+x;

2) (4·c²-2·c·d)-(-10·c²+8·c·d) =4·c²-2·c·d+10·c²-8·c·d =4·c²+10·c²-2·c·d-8·c·d =14·c²-10·c·d;

3) (12·m²-7·n-3·m·n)-(6·m·n-10·n+14·m²) =12·m²-7·n-3·m·n-6·m·n+10·n-14·m² =

=12·m²-14·m²-3·m·n-6·m·n+10·n -7·n=-2·m²-9·m·n+3·n;

4) (3·n³-2·m·n+4·m³)-(2·m·n+3·n³)=3·n³-2·m·n+4·m³-2·m·n-3·n³=

=3·n³-3·n³+4·m³-2·m·n-2·m·n=4·m³-4·m·n.