The square root of $$\left( {7 + 3\sqrt 5 } \right)$$ $$\left( {7 - 3\sqrt 5 } \right)$$ is ?
A. $$\sqrt 5 $$
B. 2
C. 4
D. $$3\sqrt 5 $$
Answer: Option B
Solution (By Examveda Team)
$$\eqalign{ & = \sqrt {\left( {7 + 3\sqrt 5 } \right)\left( {7 - 3\sqrt 5 } \right)} \cr & = \sqrt {{{\left( 7 \right)}^2} - {{\left( {3\sqrt 5 } \right)}^2}} \cr & = \sqrt {49 - 45} \cr & = \sqrt 4 \cr & = 2 \cr} $$This Question Belongs to Arithmetic Ability >> Square Root And Cube Root
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