There is more than one way to solve this problem.

Start by multiplying.

$10−4x−2=4x−8$

Simplify by adding $4x$ to each side.

$8=8x−8$

Simplify again by adding $8$ to both sides.

$16=8x$

Divide both sides by $8$.

$x=2$

See part (a) and remember to distribute the negative.

$x=4$