Answer
$x=-7$
Work Step by Step
$4-\log(3-x)=3$
Take the $4$ to substract the right side of the equation:
$-\log(3-x)=-1$
Multiply both sides by $-1$:
$\log(3-x)=1$
Write this equation in exponential form:
$3-x=10^{1}$
Solve for $x$:
$-x=10-3$
$-x=7$
$x=-7$