Appendix A - Review - A.8 Solving Equations - A.8 Assess Your Understanding - Page A70: 4

a. $x$ b. $|x-3|$

By using the facts that $\sqrt[n]{a^n}=a$ if $n$ is odd and $\sqrt[n]{a^n}=|a|$ if $n$ is even, we have: (a) Since $3$ is odd, then $\sqrt[3]{x^3}=x$ (b) Since $4$ is even, then $(\sqrt[4]{x-3})^4=|x-3|$