Question

3/x -1/y = -9 , 2/x +3/y = 5 . By substituting method

Answer 1

3/x -1/y = -9 ,
2/x +3/y = 5
substitute 1/x=a and 1/y=b

so eqn becomes
3a-b=-9.........(1)
2a-3b=5.........(2)

multiply(1) by 3
so eqn becomes
3(3a-b)=3*-9
9a-3b=-27.......(3)
Now (3)-(2)
9a-3b=-27
2a-3b=5

7a=-32
a=-32/7

sub in (2)
2*(-32/7)-3b=5
-64/7 - 3b=5
-3b=5+ 64/7
=((7*5)+64)/7
=99/7
b=(99/7)/(-3)
=(99/(7*-3))
=-33/7

so a=-32/7
1/x=-32/7
so x=1/(-32/7)
=-7/32

b=-33/7
1/y=-33/7
y=1/(-33/7)
=-7/33