Question

please tell me answer ​

Answer 1

Refer to the Attachment :-

3a+7b/3a-7b=4/3

Let say a = bk

(3bk + 7b) / (3bk - 7b)  = 4/3

=> (3k + 7)/(3k - 7) = 4/3

=> 9k + 21 = 12k - 28

=> 3k = 49

3a²-7b²/3a²+7b²

= (3(bk)² - 7b²)/(3(bk)² + 7b²)

= (3k² - 7)/(3k² + 7)

= (9k² - 21)/(9k² + 21)

= ((3k)² - 21)/((3k)² + 21)

= ( 49² - 21)/(49² + 21)

= (49 * 7 - 3) /(49 * 7 + 3)

= 340/346

= 170/173

3a²-7b²/3a²+7b² = 170/173