Rewrite the following expressions using just one rational exponent. Enter the numerator and denominator of the exponent. Cancel any common factors.
$u^{\frac{3}{2}}u^{\frac{2}{7}} = u^{\frac{a}{b}}$ where $a=$ and $b =$ .
$u^{\frac{3}{2}}u^{\frac{1}{3}} = u^{\frac{a}{b}}$ where $a=$ and $b =$ .
$u^{\frac{1}{4}}u^{\frac{1}{6}} = u^{\frac{a}{b}}$ where $a=$ and $b =$ .
Hint: You multiply two powers with the same base by adding the exponents.