Đáp án:
o) \({\dfrac{{\left( {{3^x} - {3^y}} \right)\left( {{3^{2x}} + {3^x}{{.3}^y} + {3^{2y}}} \right)}}{{{3^x} + {3^y}}}}\)
o') \({{2^{2n}} - {2^{2m}}}\)
Giải thích các bước giải:
\(\begin{array}{*{20}{l}}
{o)\dfrac{{\left( {{3^x} - {3^y}} \right)\left( {{3^{2x}} + {3^x}{{.3}^y} + {3^{2y}}} \right)}}{{{3^x} + {3^y}}}}\\
{o')\dfrac{{\left( {{{\left( {{2^{2m}}} \right)}^2} - {{\left( {{2^{2n}}} \right)}^2}} \right)}}{{{2^{2n}} + {2^{2m}}}}}\\
{{\rm{\;}} = \dfrac{{\left( {{2^{2m}} + {2^{2n}}} \right)\left( {{2^{2m}} - {2^{2n}}} \right)}}{{{2^{2n}} + {2^{2m}}}}}\\
{ = {2^{2m}} - {2^{2n}}}
\end{array}\)
