Answer
$x^{\frac{1}{2}}(x-1)$
Work Step by Step
$x^{3/2}=x^{1+\frac{1}{2}}=x^{1}\cdot x^{\frac{1}{2}}$
So,
$ x^{\frac{3}{2}}-x^{\frac{1}{2}}=x^{1}\cdot x^{\frac{1}{2}}-x^{\frac{1}{2}}\qquad$... factor out $x^{\frac{1}{2}}$
=$x^{\frac{1}{2}}(x-1)$
