Đáp án:
Giải thích các bước giải:
\[\begin{array}{l}
Bai\,\,22:\\
a){\left( { - \frac{1}{3}} \right)^2}.\left( { - \frac{1}{3}} \right) = {\left( { - \frac{1}{3}} \right)^3} = - \frac{1}{{27}}\\
b)\,\,{\left( { - 2} \right)^2}.{\left( { - 2} \right)^3} = {\left( { - 2} \right)^5} = - 32\\
c)\,\,{a^5}.{a^7} = {a^{5 + 7}} = {a^{12}}\\
Bai\,\,23:\\
a)\,\,{\left( {{2^2}} \right)^{\left( {{2^2}} \right)}} = {4^4} = 256\\
b)\,\,\frac{{{8^{14}}}}{{{8^{12}}}} = {8^{14 - 12}} = {8^2} = 64\\
c)\,\,\frac{{{{\left( { - \frac{5}{7}} \right)}^{n + 1}}}}{{{{\left( { - \frac{5}{7}} \right)}^n}}}\,\,\left( {n \ge 1} \right) = {\left( { - \frac{5}{7}} \right)^{n + 1 - n}} = {\left( { - \frac{5}{7}} \right)^1} = - \frac{5}{7}\\
Bai\,\,24:\\
a)\,\,{\left( { - \frac{2}{3}} \right)^2}.x = {\left( { - \frac{2}{3}} \right)^5}\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = {\left( { - \frac{2}{3}} \right)^5}:{\left( { - \frac{2}{3}} \right)^2}\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = {\left( { - \frac{2}{3}} \right)^3}\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = - \frac{8}{{27}}\\
b)\,\,{\left( { - \frac{1}{3}} \right)^3}.x = \frac{1}{{81}}\\
\,\,\,\,\,\,{\left( { - \frac{1}{3}} \right)^3}.x = {\left( { - \frac{1}{3}} \right)^4}\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = {\left( { - \frac{1}{3}} \right)^4}:{\left( { - \frac{1}{3}} \right)^3}\\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x = {\left( { - \frac{1}{3}} \right)^1} = - \frac{1}{3}\\
c)\,\,{\left( {2x - 3} \right)^2} = 16\\
\,\,\,\,\,\,{\left( {2x - 3} \right)^2} = {4^2}\\
\,\,\,\,\,\,\,2x - 3 = 4\,\,hoac\,\,2x - 3 = - 4\\
\,\,\,\,\,\,\,2x = 7\,\,hoac\,\,2x = - 1\\
\,\,\,\,\,\,\,x = \frac{7}{2}\,\,hoac\,\,x = - \frac{1}{2}\\
d)\,\,{\left( {3x - 2} \right)^5} = - 243\\
\,\,\,\,\,\,\,{\left( {3x - 2} \right)^5} = {\left( { - 3} \right)^5}\\
\,\,\,\,\,\,\,\,3x - 2 = - 3\\
\,\,\,\,\,\,\,\,3x = 1\\
\,\,\,\,\,\,\,\,x = \frac{1}{3}
\end{array}\]
