Answer: D. (7, 0)
Step-by-step explanation:
- [tex]4x+9y=28\\-4x-y=-28[/tex]
- The xs can already cancel since 4x is positive for the first equation, but negative on the second.
- Add the equations together
- 8y=0
- Divide both sides by 8
- y=0
- Plug y into one of the equations
- 4x + 9(0)=28
- Distribute 0
- 4x=28
- Divide both sides by 4
- x= 7
So your answer is (7, 0)