Question

(2√7-3)(2√7+3) simplify

Answer 1

Answer:

its in (a-b)x(a+b)

here a=2 root7

b=3

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

therefore,

(2 root7)^2 - (3)^2

= 14 - 9

=5 (Ans)

Answer 2

$\huge\bf{Question:-}$

Simplify:-

$(2 \sqrt{7} - 3)2 \sqrt{7} + 3)$

$\huge\bf{Solution:-}$

$(2 \sqrt{7} - 3)(2 \sqrt{7} + 3) \\ \\ Using \: Identity \\ = (a - b)(a + b) = {a}^{2} - {b}^{2} \\ = 4 \times 7 - 9 \\ = 28 - 9 \\ = 19$

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