## Algebra: A Combined Approach (4th Edition)

$x^{\frac{3}{8}}$
Step 1: Since both the radicands multiply together, their indexes add to each other. Step 2: Denoting the missing exponent by $a$, $\frac{4}{8}=\frac{1}{8}+a$ Step 3: Therefore, $a$ = $\frac{4}{8}-\frac{1}{8}$ = $\frac{3}{8}$ Step 4: The missing expression is thus $x^{\frac{3}{8}}$