Giải thích các bước giải:
\(\begin{array}{l}
1)a)\, = 2{x^3} - 14{x^2} - 6x\\
b)\, = - 8{x^4}{y^2} + 3x{y^4} - 28{x^2}{y^3}\\
c)\, = - 10{x^5} - 15{x^4} + 25{x^3}\\
d)\, = - 6{x^5} + {x^4}y - 3{x^3}{y^2}\\
e)\, = {x^3} + 4{x^2} - 2{x^2} - 8x + 3x + 12\\
= {x^3} + 2{x^2} - 5x + 12\\
f)\, = 10{x^4} + 4{x^3} - 15{x^2} - 6x - 5x - 2\\
= 10{x^4} - 11{x^3} - 11x - 2\\
2)\,a) = 4{x^2} + 12xy + 9{y^2}\\
b)\, = 25{x^2} - 10xy + {y^2}\\
c)\, = {x^2} + \dfrac{x}{2} + \dfrac{1}{{16}}\\
d)\, = {x^4} - \dfrac{4}{{25}}{y^2}\\
e)\, = 8{x^3} + 12{x^2}{y^2} + 6x{y^4} + 8{y^6}\\
f) = 27{x^6} - 54{x^4}y + 36{x^2}{y^2} - 8{y^3}\\
g)\, = {x^3} - {4^3}\\
h) = {x^6} - \dfrac{1}{{27}}\\
3)\,a) = {\left( {892 + 108} \right)^2} = {1000^2}\\
b) = {\left( {36 - 26} \right)^2} = {100^2}
\end{array}\)