Answer :

99x+101y=1499
101x+99y=1501
First we will add the equations,
99x+101x+101y+99y=3000
200x+200y=3000
200(x+y)=3000
x+y=3000/200=15....(i)
Second we will subtract the equations,
101x+99y=1501
99x+1101y=1499
2(x-y)=2
x-y=1....(ii)
From equation (i) and (ii),we get
x+y=15
x-y=1
By adding we get,
2x=16
x=16/2=8
Now we get,y also which is 7
Hope this helps you.
99x+101y=1499
101x+99y=1501
First we will add the equations,
99x+101x+101y+99y=3000
200x+200y=3000
200(x+y)=3000
x+y=3000/200=15....(i)
Second we will subtract the equations,
101x+99y=1501
99x+1101y=1499
2(x-y)=2
x-y=1....(ii)
From equation (i) and (ii),we get
x+y=15
x-y=1
By adding we get,
2x=16
x=16/2=8
Now we get,y also which is 7
Hope this helps you.