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View Full Version : Radical expression (adding and subtracting)


sasha195
Sep 25, 2008, 04:23 PM
√99+√63-√144=

Unknown008
Sep 26, 2008, 03:45 AM
You can do them in a calculator, each one, and do the remaining calculations... or you mean simplifying? Then here we go!

\sqrt{99}

divide by a square number you know, 9. The square root of 9 is 3. ok:

\sqrt{99} = \sqrt{11\times9} = \sqrt{9} \times \sqrt{11} = 3 \times \sqrt{11}=3\sqrt{11}

\sqrt{63}

Same thing:
\sqrt{63} = \sqrt{7\times9} = \sqrt9 \times \sqrt7 = 3 \times \sqrt7=3\sqrt7

and

\sqrt{144}

is 12, giving;

3\sqrt{11} + 3\sqrt7 - 12

Then you can further simplify, 3(\sqrt{11} + \sqrt7) - 12