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Simplifying 25+144\sqrt{25} + \sqrt{144} versus 25+144\sqrt{25 + 144}

Simplify two expressions that use the same numbers but differ in whether the addition is inside or outside the radical, showing that the results are not equal.

25+144=17\sqrt{25} + \sqrt{144} = 17: Each radical contains only a single number, so evaluate each square root separately using the order of operations: 25=5\sqrt{25} = 5 and 144=12\sqrt{144} = 12. Then add: 5+12=175 + 12 = 17.

25+144=13\sqrt{25 + 144} = 13: Because the radical sign acts as a grouping symbol, simplify the expression under the radical first: 25+144=16925 + 144 = 169. Then take the square root: 169=13\sqrt{169} = 13.

The two results — 17 and 13 — are different, which demonstrates that a+b\sqrt{a} + \sqrt{b} is generally not equal to a+b\sqrt{a + b}. The placement of the addition — outside or inside the radical — fundamentally changes which operation is performed first and therefore changes the outcome.

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Updated 2026-04-21

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