Упр.10.4 ГДЗ Мерзляк Поляков 7 класс (Алгебра)

1) (3x^2-2x)+(-x^2+3x);
2) (4c^2-2cd)-(10c^2+8cd);
3) (12m^2-7n-3mn)-(6mn-10n+14m^2 );
4) (3n^3-2mn+4m^3 )-(2mn+3n^3 ).

1. $$\begin{aligned}
   (3x^2-2x)+(-x^2+3x) &= 3x^2-2x-x^2+3x \\
   &= 2x^2+x
   \end{aligned}$$
2. $$\begin{aligned}
   (4c^2-2cd)-(10c^2+8cd) &= 4c^2-2cd-10c^2-8cd \\
   &= -6c^2-10cd
   \end{aligned}$$
3. $$\begin{aligned}
   (12m^2-7n-3mn)-(6mn-10n+14m^2) &= 12m^2-7n-3mn-6mn+10n-14m^2 \\
   &= -2m^2+3n-9mn
   \end{aligned}$$
4. $$\begin{aligned}
   (3n^3-2mn+4m^3)-(2mn+3n^3) &= 3n^3-2mn+4m^3-2mn-3n^3 \\
   &= 4m^3-4mn
   \end{aligned}$$

Ответ

1) $$2x^2+x$$; 2) $$-6c^2-10cd$$; 3) $$-2m^2+3n-9mn$$; 4) $$4m^3-4mn$$.