Đáp án:
$\begin{array}{l}
a)M = {x^2} - 8x + 7\\
= {x^2} - 7x - x + 7\\
= \left( {x - 7} \right)\left( {x - 1} \right)\\
= \left( {49 - 7} \right)\left( {49 - 1} \right)\\
= 42.48\\
= 2016\\
b)N = {x^4} - 2{x^3} + {x^2}\\
= {x^2}\left( {{x^2} - 2x + 1} \right)\\
= {x^2}.{\left( {x - 1} \right)^2}\\
= {10^2}.{\left( {10 - 1} \right)^2}\\
= {100.9^2}\\
= 8100\\
c)P = {m^6} - 2{m^4} - m + {m^2} + {m^3}\\
= {m^6} - {m^4} + 2{m^3} - {m^4} + {m^2} - 2m\\
- {m^3} + m + 2 - 2\\
= {m^3}\left( {{m^3} - m + 2} \right) - m\left( {{m^3} - m + 2} \right)\\
- \left( {{m^3} - m + 2} \right) - 2\\
= \left( {{m^3} - m + 2} \right)\left( {{m^3} - m - 1} \right) - 2\\
= 0.\left( {{m^3} - m - 1} \right) - 2\\
= - 2
\end{array}$
