how do i get 6 on the problem x/-2-4=-7
Like this:\(\begin{align} -\frac{x}{2}-4&=-7 \; /\cdot(-2)\\ \frac{x(-2)}{-2}-4(-2)&=-7(-2)\\ x+8&=14\\ x&=14-8\\ x&=6 \end{align}\)
+16 
