## Algebra and Trigonometry 10th Edition

$x^{\frac{3}{2}}+21=13$ $x^{\frac{3}{2}}=13-21$ $x^{\frac{3}{2}}=-8~~$ (Square both sides): $(x^{\frac{3}{2}})^2=(-8)^2$ $x^3=64$ $x=\sqrt[3] {64}=4$ Check the solution: $4^{\frac{3}{2}}+21=(\sqrt 4)^3+21=8+21=29\ne13$