#### Answer

$-2$

#### Work Step by Step

Distribute 4 to each term in the brackets on the left hand side.
$8x-4(3-x)+20=-6x-28$
Distribute $-4$ to the terms in the parentheses.
$8x-12+4x+20=-6x-28$
Combine like terms on the left hand side.
$12x+8=-6x-28$
Add $6x$ to both sides.
$18x+8=-28$
Subtract 8 from both sides.
$18x=-36$
Divide both sides by 18.
$x=-2$