a) $(2x-3)^2=9$
\(⇒\left[ \begin{array}{l}2x-3=3\\2x-3=-3\end{array} \right.\)
\(⇒\left[ \begin{array}{l}2x=6\\2x=0\end{array} \right.\)
\(⇒\left[ \begin{array}{l}x=3\\x=0\end{array} \right.\)
b) $(x-1)^7=(x-1)^3$
\(⇒\left[ \begin{array}{l}(x-1)^7=0⇒x=1\\(x-1)^3=0⇒x=1\end{array}⇒x=1 (tm) \right.\)
\(⇒\left[ \begin{array}{l}(x-1)^7=1⇒x=2\\(x-1)^3=1⇒x=2\end{array}⇒x=2(tm) \right.\)
\(⇒\left[ \begin{array}{l}(x-1)^7=-1⇒x=0\\(x-1)^3=-1⇒x=0\end{array}⇒x=0(tm) \right.\)
c) $7^2-(13+4x)=5.2^3$
$49-(13+4x)=5.8=40$
$13+4x=49-40=9$
$4x=9-13=-4$
$⇒x=-1$
d) $x^5=x^3$
\(⇒\left[ \begin{array}{l}x^5=1⇒x=1\\x^3=1⇒x=1\end{array}⇒x=1 \right.\)
\(⇒\left[ \begin{array}{l}x^5=-1⇒x=-1\\x^3=-1⇒x=-1\end{array}⇒x=-1 \right.\)
\(⇒\left[ \begin{array}{l}x^5=0⇒x=0\\x^3=0⇒x=0\end{array}⇒x=0 \right.\)
