Question

What is the solution of 3x + y = 9 and 3x − 5y = 15?

Answer 1

3x+y=9
3x-5y=15

3x+y+6=3x-5y
y+6=-5y
6y=-6
y=-1

3x-1=9
3x=10
x=10/3
x=3 1/3

y=-1
x=3 1/3

Hope this helps :)

Answer 2

3x+y=9 ....(1)
3x-5y=15. ......(2)
-[3x-5y=15]
=> 3x+ y = 9
-3x+5y=-15
..........................
0 +6y=-6
so,y=-1
3x+(-1)=9
3x=10
x=10/3