There are two fractions containing $x$ and the denominators are different. First, let us find a common denominator to simplify the expression. The least common multiplier of 4 and 7 is 28 . Then,

$7(x-2) / 28-4(3 x+5) / 28=-3 \cdot 28 / 28 \ldots$ Since both sides are written on the denominator 28 now, we can eliminate them:

$7(x-2)-4(3 x+5)=-84$

$7 x-14-12 x-20=-84$

$-5 x=-84+14+20$

$-5 x=-50$

$x=50 / 5$

$x=10$