Answer
$x=-1\frac{1}{3}$
Work Step by Step
$3x+4=0$ $\longrightarrow$ addition property of equality
$3x+4-4=0-4$ $\longrightarrow$ combine like terms
$3x=-4$ $\longrightarrow$ multiplication property of equality
$3x\div3=-4\div3$ $\longrightarrow$ divide
$x=-\frac{4}{3}$ $\longrightarrow$ simplify
$x=-1\frac{1}{3}$
