#### Answer

$x=19$

#### Work Step by Step

If you have trouble following the steps below, please review the order of operations (PEMDAS) or the distributive property. Note that, because we are told that $y=0$, the expression involving $x$ is also equal to zero.
$y=4[x-(3-x)]-7(x+1)=0$
$4(x-3+x)-7x-7=0$
$4(2x-3)-7x-7=0$
$8x-12-7x-7=0$
$x-19=0$
$x=19$