#### Answer

$x=-9$

#### Work Step by Step

$x+20+2x=-10-2x-15$ $\longrightarrow$ simplify
$3x+20=-25-2x$ $\longrightarrow$ addition property
$3x+20-20+2x=-25-2x-20+2x$ $\longrightarrow$simplify
$5x=-45$\multiplication property
$5x\div5=-45\div 5$ $\longrightarrow$simplify
$x=-9$