Question

If 3x+5y=10 and 3y+5x=30 then average if ‘x’ and ‘y’ is?

Answer 1

3x+5y=10
5x+3y=30
multiply eq1 with 5 and eq2 with 3
15x+25y=50
15x+9y=90
16y=-40
y=-40/16
y=-10/4
y=-5/2
now
3x+5(-5/2)=10
3x-25/2 =10
3x=10+25/2
3x=2*10+25/2
3x=20+25/2
3x=45/2
x=45/6
x=15/2
x=15/2,y=-5/2
average
15/2 -5/2 /2
10/2 /2
5/2
2.5 is answer obtained