Question

which of the following is the value of
$( \sqrt{11} - \sqrt{7} )( \sqrt{11} - \sqrt{7} )$
(a) -4
(b) 4

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Answer 1

Answer :-

• (b) 4 is the answer.

Given :-

$( \sqrt{11} - \sqrt{7})( \sqrt{11} + \sqrt{7})$

To Find we need to know :-

To solve this , we need to know a formula which is given below :-

$\rm{ \huge[}(a + b)\: (a - b) = {a}^{2} - {b}^{2} \huge ]$

So, let's solve :-

$\mapsto( \sqrt{11} - \sqrt{7})( \sqrt{11} + \sqrt{7})$

Now, applying the rule we get ,

$\mapsto( \sqrt{11 } )^{2} - (\sqrt{7} )^{2}$

Now , removing square root as well as square , then the no. wouldn't be square also or square root also. It will remain same except the square and square root .

$\mapsto11 - 7$

$\mapsto \bf4$

$\therefore \rm \: \bf4 \: is \: the \: ans$

_________________________________

which of the following is the value of

$( \sqrt{11} - \sqrt{7} )( \sqrt{11} - \sqrt{7} )$

(a) -4

(b) 4 ✔