Solve for x and y:
We have
and
Lets simplify these equations. Assuming p = 1/(x + y) and q = 1/(x – y),
3p + 2q = 2 …(i)
Also,
⇒ 9p – 4q = 1 …(ii)
To solve these equations, we need to make one of the variables (in both the equations) have same coefficient.
Lets multiply eq.(i) by 3, so that variable p in both the equations have same coefficient.
Recalling equations (i) & (ii),
3p + 2q = 2 [×3
9p – 4q = 1
⇒ 10q = 5
⇒ q = 1/2
Substitute q = 1/2 in eq.(i)/eq.(ii), as per convenience of solving.
Thus, substituting in eq.(i), we get
3p + 2(1/2) = 2
⇒ 3p + 1 = 2
⇒ 3p = 2 – 1 = 1
⇒ p = 1/3
Thus, p = 1/3 and q = 1/2
As p = 1/(x + y),
⇒
⇒ x + y = 3 …(iii)
And q = 1/(x – y)
⇒
⇒ x – y = 2 …(iv)
Adding equations (iii) and (iv) to obtain x and y,
(x + y) + (x – y) = 3 + 2
⇒ 2x = 5
⇒ x = 5/2
Putting the value of x in equation (iii), we get
5/2 + y = 3
⇒ y = 3 – 5/2
⇒ y = 1/2
Hence, we have x = 5/2 and y = 1/2