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Question

What will come in place of ? to satisfy the equation : $(\sqrt{6}-1)^2 = ? - 2\sqrt{6}$

This question was previously asked in
SSC CGL 2025 Tier 2 Paper 1 Question Paper (19-Jan-2026)
The correct answer is
7

Expand the Equation

The problem requires finding the value that satisfies the equation: $ (\sqrt{6}-1)^2 = ? - 2\sqrt{6} $ First, expand the left side, $ (\sqrt{6}-1)^2 $, using the algebraic identity $ (a-b)^2 = a^2 - 2ab + b^2 $. Here, $ a = \sqrt{6} $ and $ b = 1 $. $ (\sqrt{6}-1)^2 = (\sqrt{6})^2 - 2(\sqrt{6})(1) + (1)^2 $ $ (\sqrt{6}-1)^2 = 6 - 2\sqrt{6} + 1 $ $ (\sqrt{6}-1)^2 = 7 - 2\sqrt{6} $

Solve for the Unknown

Now, substitute the expanded form back into the original equation: $ 7 - 2\sqrt{6} = ? - 2\sqrt{6} $ To isolate the question mark (?), add $ 2\sqrt{6} $ to both sides of the equation: $ 7 - 2\sqrt{6} + 2\sqrt{6} = ? - 2\sqrt{6} + 2\sqrt{6} $ $ 7 = ? $ Thus, the value that comes in place of ? is 7.

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