2.
Solve by elimination:
...(1) .. multiply both sides by ...(2)
...(1) . subtract (2) from (1)
- ...(2)
------------------------------------------ .divide both sides by
3.
Solve by substitution:
...(1) substitute (2) in (1) (2)
...(1) ...(1) ...(1) move from the left to the right ...(1)
...(1) divide both sides by ...(1)
...(1) now substitute in (2)
