Question

if a²+b²=74 and ab=35, then find a+b

Answer 1

Hi there !

________________________,

• Given :

a² + b² = 74

ab = 35.

• To find :

Value of a + b

• Solution :

To solve the question, we need to know about the following identity :

( a + b )² = a² + b² + 2ab

On substituting the value of a²+b² = 74 and ab = 35, we get ;

( a + b )² = a² + b² + 2ab

=> ( a + b )²  = 74 + 2 × 35

=> ( a + b )²  = 74 + 70

=> ( a + b )²  = 144

=> ( a + b ) = √144

=> ( a + b ) = 12.

Therefore,

The value of (a + b) = 12.

___________________________

Thanks for the question !

❤❤❤❤

Answer 2

Answer :-

_________________________


• Given :-


a² + b² = 74


ab = 35


•To find :-


The value of : a + b


• Salutation :-


a² + b² = 74


( a + b )² - 2ab = 74


[ • a² + b² = ( a + b )² - 2 ab → Using this identity ]


( a + b )² - 2 × 35 = 74 [ • Putting the value of ab as given ]


( a + b )² - 70 = 74


( a + b )² = 74 + 70


( a + b )² = 144


( a + b )² = ( 12 )²


( a + b ) = 12 [ Required answer ]


__________________


Note :-


a² + b² = ( a + b )² - 2 ab ----- ( i )


a² + b² = ( a - b )² + 2ab ----- ( ii )


We can use both of the identity as needed but to find this salutation we used the ( i ) identity.

___________________________

★ Be Brainly ★