On Tue, Feb 9, 2010 at 6:59 PM, indra priyadarsini wrote:
I received your reply. I’ll send my solutions as soon as possible to the mentioned address.
As I was going through some of the sample papers I had, I came across the following problem. I could not solve it for a long time. Finally I got the answer as 42.666. Since the solutions were not given, I request you to kindly check my answer and let me know. If my answer is wrong, please let me know the right answer along with the working.
If 5x – 11y = 2x + 5y, then find the value of 3x^2 + 2y^2 / 3x^2 – 2y^2
3x = 16y
x = 16 / 3y ………………[eq. 1]
(3x^2 + 2y^2) + (3x^2 – 2y^2) / (3x^2 + 2y^2) – (3x^2 – 2y^2) [By Componendo & Dividendo]
= (3x^2 + 2y^2 + 3x^2 – 2y^2) / (3x^2 + 2y^2 – 3x^2 + 2y^2)
= 6x^2 / 4y^2
= 3x^2 / 2y^2
= 3(16 / 3y)^2 / 2y^2 [On substituting x from eq.1]
= 3*256*y^2 / 2*9*y^2
You have solved it right.