Answer
$x=-2$
Work Step by Step
The distributive property allows us to distribute anything multiplied by something inside of the parenthesis to whatever is inside of the parenthesis. Thus, we distribute the 5 to everything inside of the first set of parenthesis, the -1 to everything inside of the second set of parenthesis, and the 4 to everything in the third set of parenthesis, giving us the equation 10x-5-3x-4=4x+12-27. We now simplify:
$7x-9=4x-15 \\\\ 3x-9=-15 \\\\ 3x=-6 \\\\ x=-2$