English
Maharashtra State BoardSSC (English Medium) 9th Standard

If ab=23 then find the value of the following expression. 5a2+2b25a2-2b2 - Algebra

Advertisements
Advertisements

Question

If `bb(a/b = 2/3)` then find the value of the following expression.

`[5a^2 + 2b^2]/[ 5a^2 - 2b^2]`

Sum

Solution

`a/b = 2/3`

Squaring both sides,

⇒ `a^2/b^2 = 4/9`     

⇒ `(5a^2)/(2b^2) = [5 xx 4]/[2 xx 9]`

⇒ `(5a^2)/(2b^2) = 20/18` 

Applying componendo and dividendo, we get

`[5a^2 + 2b^2]/[ 5a^2 - 2b^2] = [20+18]/[20-18]`

⇒ `[5a^2 + 2b^2]/[ 5a^2 - 2b^2] = [38]/[2]`

⇒ `[5a^2 + 2b^2]/[ 5a^2 - 2b^2] = 19`                    

shaalaa.com
Operations on Equal Ratios
  Is there an error in this question or solution?
Chapter 4: Ratio and Proportion - Problem Set 4 [Page 78]

APPEARS IN

Balbharati Algebra (Mathematics 1) [English] 9 Standard Maharashtra State Board
Chapter 4 Ratio and Proportion
Problem Set 4 | Q (8) (ii) | Page 78
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×