2x+9=20

Solve for x:

• 2x + 9 = 20
• Subtract 9 from both sides: 2x = 11
• Divide both sides by 2: x = 11/2

Check: 2*(11/2) + 9 = 11 + 9 = 20 ✓

So, x = 11/2 (or 5.5).