(5- \sqrt{ 7 } \times (2- \sqrt{ 7) }
Evaluate
12-2\sqrt{7}\approx 6.708497378
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5-\left(2\sqrt{7}-\left(\sqrt{7}\right)^{2}\right)
Use the distributive property to multiply \sqrt{7} by 2-\sqrt{7}.
5-\left(2\sqrt{7}-7\right)
The square of \sqrt{7} is 7.
5-2\sqrt{7}-\left(-7\right)
To find the opposite of 2\sqrt{7}-7, find the opposite of each term.
5-2\sqrt{7}+7
The opposite of -7 is 7.
12-2\sqrt{7}
Add 5 and 7 to get 12.
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