\(1.\)
\(b,\left(4.2^5\right)\div\left(2^3.\dfrac{1}{16}\right)=\left(2^2.2^5\right)\div\dfrac{1}{2}=2^7\div\dfrac{1}{2}=2^7.2=2^8\)
\(2.\)
\(b,\left(-\dfrac{1}{3}\right).x=\dfrac{1}{81}\)
\(x=\dfrac{1}{81}\div\left(-\dfrac{1}{3}\right)\)
\(x=-\dfrac{1}{27}\)
\(c,\left(2x-3\right)^2=16\)
\(\left(2x-3\right)^2=4^2\)
\(2x=4+3\)
\(2x=7\)
\(x=7\div2\)
\(x=\dfrac{7}{2}\)
\(3.\)
\(a,\left(\dfrac{2}{3}x-\dfrac{1}{3}\right)^5=\dfrac{1}{243}\)
\(\left(\dfrac{2}{3}x-\dfrac{1}{3}^5\right)=\left(\dfrac{1}{3}\right)^5\)
\(\dfrac{2}{3}x=\dfrac{1}{3}+\dfrac{1}{3}\)
\(\dfrac{2}{3}x=\dfrac{2}{3}\)
\(x=\dfrac{2}{3}\div\dfrac{2}{3}\)
\(x=1\)
\(b,\left(\dfrac{2}{5}-3x\right)^2=\dfrac{9}{25}\)
\(\left(\dfrac{2}{5}-3x\right)^2=\left(\dfrac{3}{5}\right)^2\)
\(3x=\dfrac{2}{5}-\dfrac{3}{5}\)
\(3x=\dfrac{-1}{5}\)
\(x=-\dfrac{1}{5}\div3\)
\(x=-\dfrac{1}{15}\)
\(c,\left(x-\dfrac{3}{5}\right)^2=4\)
\(\left(x-\dfrac{3}{5}\right)^2=2^2\)
\(x=2+\dfrac{3}{5}\)
\(x=\dfrac{13}{5}\)
