3) Даны многочлены a) P= -3,200+ 1,806 -1,363, Q=1,80-1, 2ab + 1,363, Hansa: Q-P 5)P=363-6²+6; Q=2²+b²-b Найти: P-Q

3) Даны многочлены: a) $$P = -3,2a^3 + 1,8ab - 1,3b^3$$, $$Q = 1,8a^3 - 1,2ab + 1,3b^3$$, Найти: Q - P

$$Q - P = (1,8a^3 - 1,2ab + 1,3b^3) - (-3,2a^3 + 1,8ab - 1,3b^3) = 1,8a^3 - 1,2ab + 1,3b^3 + 3,2a^3 - 1,8ab + 1,3b^3 = (1,8a^3 + 3,2a^3) + (-1,2ab - 1,8ab) + (1,3b^3 + 1,3b^3) = 5a^3 - 3ab + 2,6b^3$$

б) $$P = \frac{3}{8}b^3 - \frac{2}{9}b^2 + \frac{1}{6}b$$, $$Q = \frac{3}{4}b^3 + \frac{2}{3}b^2 - \frac{1}{3}b$$, Найти: P - Q

$$P - Q = (\frac{3}{8}b^3 - \frac{2}{9}b^2 + \frac{1}{6}b) - (\frac{3}{4}b^3 + \frac{2}{3}b^2 - \frac{1}{3}b) = \frac{3}{8}b^3 - \frac{2}{9}b^2 + \frac{1}{6}b - \frac{3}{4}b^3 - \frac{2}{3}b^2 + \frac{1}{3}b = (\frac{3}{8}b^3 - \frac{3}{4}b^3) + (-\frac{2}{9}b^2 - \frac{2}{3}b^2) + (\frac{1}{6}b + \frac{1}{3}b) = (\frac{3}{8}b^3 - \frac{6}{8}b^3) + (-\frac{2}{9}b^2 - \frac{6}{9}b^2) + (\frac{1}{6}b + \frac{2}{6}b) = -\frac{3}{8}b^3 - \frac{8}{9}b^2 + \frac{3}{6}b = -\frac{3}{8}b^3 - \frac{8}{9}b^2 + \frac{1}{2}b$$

Ответ: a) $$5a^3 - 3ab + 2,6b^3$$, б) $$\frac{-3}{8}b^3 - \frac{8}{9}b^2 + \frac{1}{2}b$$