a)

\(P \left(\right. x \left.\right) =\)\(3 x^{2} + 7 + 2 x^{4} - 3 x^{2} - 4 - 5 x + 2 x^{3}\)

\(= \left(\right. 3 x^{2} - 3 x^{2} \left.\right) + 2 x^{4} + 2 x^{3} - 5 x + \left(\right. 7 - 4 \left.\right)\)

\(= 2 x^{4} + 2 x^{3} - 5 x + 3\)

\(Q \left(\right. x \left.\right) =\)\(3 x^{3} + 2 x^{2} - x^{4} + x + x^{3} + 4 x - 2 + 5 x^{4}\)

\(= \left(\right. 5 x^{4} - x^{4} \left.\right) + \left(\right. 3 x^{3} + x^{3} \left.\right) + 2 x^{2} + \left(\right. x + 4 x \left.\right) - 2\)

\(= 4 x^{4} + 4 x^{3} + 2 x^{2} + 5 x - 2\)

\(b \left.\right)\)

\(P \left(\right. - 1 \left.\right) = \&\text{nbsp}; 2 * \left(\right. - 1 \left.\right)^{4} + 2 * \left(\right. - 1 \left.\right)^{3} - 5 * \left(\right. - 1 \left.\right) \&\text{nbsp}; + 3\)

\(= 2 * 1 + 2 * \left(\right. - 1 \left.\right) + 5 + 3\)

\(= 2 - 2 + 5 + 3\)

\(= 8\)

___

\(Q \left(\right. 0 \left.\right) = 4 * 0^{4} + 4 * 0^{3} + 2 * 0^{2} + 5 * 0 \&\text{nbsp}; - 2\)

\(= 4 * 0 + 4 * 0 + 2 * 0 + 5 * 0 - 2\)

\(= - 2\)

c dễ

đấm nhau không