Step 1. Expand
-3x - 4 = 5x + 20
Step 2. Add 3x to both sides
-4 = 5x + 20 + 3x
Step 3. Simplify 5x + 20 + 3x to 8x + 20
-4 = 8x + 20
Step 4. Subtract 20 from both sides
-4 - 20 = 8x
Step 5. Simplify -4 - 20 to -24
-24 = 8x
Step 6. Divide both sides by 8
-24/8 = x
Step 7. Simplify 24/8 to 3
-3 = x
Step 8. Switch sides
x = -3