#### Answer

When $x=-6$, the value of $y$ is $-30$.

#### Work Step by Step

$y$ varies directly so its equation is of the form $y=kx$.
When $y=20$, $x=4$. Substitute these values into $y=kx$ to obtain:
$y=kx
\\20=k(4)
\\\frac{20}{4}=\frac{k(4)}{4}
\\5=k$
Thus, the direct variation is $y=5x$.
To find the value of $y$ when $x=-6$, substitute $-6$ to $x$ in the equation above to obtain:
$y=5x
\\y=5(-6)
\\y=-30$