Evaluate
\frac{3\left(\sqrt{2}+4\right)}{7}\approx 2.320377241
Factor
\frac{3 {(\sqrt{2} + 4)}}{7} = 2.3203772410170407
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\frac{\left(6+3\sqrt{2}\right)\left(3-\sqrt{2}\right)}{\left(3+\sqrt{2}\right)\left(3-\sqrt{2}\right)}
Rationalize the denominator of \frac{6+3\sqrt{2}}{3+\sqrt{2}} by multiplying numerator and denominator by 3-\sqrt{2}.
\frac{\left(6+3\sqrt{2}\right)\left(3-\sqrt{2}\right)}{3^{2}-\left(\sqrt{2}\right)^{2}}
Consider \left(3+\sqrt{2}\right)\left(3-\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+3\sqrt{2}\right)\left(3-\sqrt{2}\right)}{9-2}
Square 3. Square \sqrt{2}.
\frac{\left(6+3\sqrt{2}\right)\left(3-\sqrt{2}\right)}{7}
Subtract 2 from 9 to get 7.
\frac{18-6\sqrt{2}+9\sqrt{2}-3\left(\sqrt{2}\right)^{2}}{7}
Apply the distributive property by multiplying each term of 6+3\sqrt{2} by each term of 3-\sqrt{2}.
\frac{18+3\sqrt{2}-3\left(\sqrt{2}\right)^{2}}{7}
Combine -6\sqrt{2} and 9\sqrt{2} to get 3\sqrt{2}.
\frac{18+3\sqrt{2}-3\times 2}{7}
The square of \sqrt{2} is 2.
\frac{18+3\sqrt{2}-6}{7}
Multiply -3 and 2 to get -6.
\frac{12+3\sqrt{2}}{7}
Subtract 6 from 18 to get 12.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}