#### Answer

$x=-15$

#### Work Step by Step

$6x+3-(-x)=-20+5x-7$ $\longrightarrow$combine like terms
$7x+3=-27+5x$ $\longrightarrow$addition property
$7x+3-5x-3=-27+5x-5x-3$ $\longrightarrow$combine like terms
$2x=-30$ $\longrightarrow$multiplication property
$2x\div2=-30\div2$ $\longrightarrow$simplify
$x=-15$