Answer:
1. C.20
2. C.22
Step-by-step explanation:
For the first question you would set up the equation 3x+7+5x+13=180. You would combine like terms, getting 8x+20=180, subtract 20 from both sides, getting 8x=160, then divide both sides, getting x as 20. For the second question you would set up the equation 5x+5x-40=180. You would combine like terms, getting 10x-40=180, add 40 to both sides, getting 10x=220, then divide both sides by 10, getting x as 22.
