Question

(7 + √7) (7 - √7) = _____
(a) 0
(b) 2√7
(c)7√7
(d) 42

Answer 1

HEY MATE...
HERE IS THE ANSWER ✌
____________⬇⬇⬇

USING FORMULA
(a+b)(a-b)=a sq.- b sq.

so,
(7+√7)(7-√7)=7 sq. -√7 sq.
=49-7=42...

it means d option is correct.
________

Answer 2

Answer : 42

Explanation :-

Given :

(7 + √7) (7 - √7) = _____

Using identity :-

(a + b) (a - b) = a^2 - b^2

(7 + √7) (7 - √7) = 7^2 - √7^2

=> 7^2 - √7^2

=> √7 = 2.6

=> 7 x 7 - 2.6 x 2.6

=> 49 - 6.76

=> 42.

Hence, answer is 42.