Answer
$g=-2$
Work Step by Step
Step 1: $\frac{8+g}{2}-7=-4$
Step 2: Add 7 to both sides: $\frac{8+g}{2}-7+7=-4+7$.
Step 3: $\frac{8+g}{2}=3$
Step 4: Multiply both sides by 2: $\frac{8+g}{2}\times2=3\times2$.
Step 5: $8+g=6$
Step 6: Subtract 8 from both sides: $8+g-8=6-8$.
Step 7: $g=-2$