Answer
$\frac{-10}{21}$
Work Step by Step
$\frac{5}{7}$$\times$$\frac{-2}{3}$
Whenever you multiply a fraction, you multiply top and bottom
$\frac{5x(-2)}{7\times3 }$
so the result is $\frac{-10}{21}$
you can't reduce more so that is the solution
