Evaluate
\frac{13-5\sqrt{2}}{7}\approx 0.846990313
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\frac{\left(6-\sqrt{2}\right)\left(4-\sqrt{2}\right)}{\left(4+\sqrt{2}\right)\left(4-\sqrt{2}\right)}
Rationalize the denominator of \frac{6-\sqrt{2}}{4+\sqrt{2}} by multiplying numerator and denominator by 4-\sqrt{2}.
\frac{\left(6-\sqrt{2}\right)\left(4-\sqrt{2}\right)}{4^{2}-\left(\sqrt{2}\right)^{2}}
Consider \left(4+\sqrt{2}\right)\left(4-\sqrt{2}\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.
\frac{\left(6-\sqrt{2}\right)\left(4-\sqrt{2}\right)}{16-2}
Square 4. Square \sqrt{2}.
\frac{\left(6-\sqrt{2}\right)\left(4-\sqrt{2}\right)}{14}
Subtract 2 from 16 to get 14.
\frac{24-6\sqrt{2}-4\sqrt{2}+\left(\sqrt{2}\right)^{2}}{14}
Apply the distributive property by multiplying each term of 6-\sqrt{2} by each term of 4-\sqrt{2}.
\frac{24-10\sqrt{2}+\left(\sqrt{2}\right)^{2}}{14}
Combine -6\sqrt{2} and -4\sqrt{2} to get -10\sqrt{2}.
\frac{24-10\sqrt{2}+2}{14}
The square of \sqrt{2} is 2.
\frac{26-10\sqrt{2}}{14}
Add 24 and 2 to get 26.
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