Answer:
1. Find an expression(s) that can be eliminated.
2. Add the equations together (plus and minus & minus and plus) such that they cancel each other out.
Step-by-step explanation:
E.g.
2x +5 = 15 -----1
3x + 5 = 20 -----2
We are gonna eliminate 5 since it occurs in both equations.
2-1: 3x-2x+5-5 = 20-15
(+5-5) = 0, we are left with the x.
x = 5.
