Question

solve this question anyone ​

Answer 1

Given :

(a-b) = 7 and ab = 18

To find out :

i ) a+b

• Solution :-

Using :- (a-b)² = a² + b² - 2ab

=> (7)² = a² + b² - 2(18)

=> 49 = a² + b² - 36

=> a² + b² = 49 + 36

=> a² + b² = 85 ________[equation -1]

Now substituting [equation -1] in:-

=> (a+b)² = a² + b² + 2ab

=> (a+b)² = 85 + 2(18)

=> (a+b)² = 85 + 36

=> (a+b)² = 121

=> a+b = 11

_______________________________________

ii ) a² - b²

• Solution :-

Using :- a² - b² = (a+ b)(a-b)

=> a² - b² = ( 11 )( 7 )

=> a² - b² = 77

$\huge{\boxed{\red{\bf{Answer:}}}}$

i ) a + b = 11

ii ) a² - b² = 77