3a + b = 5 2a - b = 5

3a+b=5
2a-b=5
______ +
5a=10
a=10/5
a=2


3a+b=5
3(2)+b=5
6+b=5
b=-1

metode eliminasi..
3a + b = 5
2a - b = 5
________ +
5a = 10
a = 10/5
a = 2

metode subtitusi u/a = 2
3a + b = 5
3(2) + b = 5
6 + b = 5
b = 5 - 6
b = -1

jadi, a = 2 dan b = -1

smoga btmanfaat.