Question

Find the value of (√11- √7) ( √11+ √7)

Answer 1

Answer:

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

So,

(√11+√7)(√11-√7)

= (√11)^2-(√7)^2 = 11-7 = 4

Hope this helps you !

Answer 2

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To find value of

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

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Here! The given form of value is in form of equation identity known as ...

$(a + b)(a - b) = {a}^{2} - {b}^{2}$

So! Here! we are going to change the value of the given eqn according to the identity. So it will be ...

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

$\sqrt{11^{2} } - \sqrt{7^{2} }$

Here! the square root will be itself only.

$11 - 7$

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