Question

What is the answer to this question

Answer 1

First you bring the 9 over with the seven 
$-2= \sqrt[3]{x+9}$
Now cube both sides
$-8=x+9$
Finally subtract 9 over and get
$x=-17$


Check
$7=9+ \sqrt[3]{-17+9}$
$7=9+ \sqrt[3]{-8}$
$7=9+(-2)$
7=7