Evaluate
-\frac{\sqrt{3}}{3}-\frac{\sqrt{21}}{7}-\sqrt{6}\approx -3.681493683
Share
Copied to clipboard
2\sqrt{6}-\sqrt{\frac{1}{3}}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Factor 24=2^{2}\times 6. Rewrite the square root of the product \sqrt{2^{2}\times 6} as the product of square roots \sqrt{2^{2}}\sqrt{6}. Take the square root of 2^{2}.
2\sqrt{6}-\frac{\sqrt{1}}{\sqrt{3}}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Rewrite the square root of the division \sqrt{\frac{1}{3}} as the division of square roots \frac{\sqrt{1}}{\sqrt{3}}.
2\sqrt{6}-\frac{1}{\sqrt{3}}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Calculate the square root of 1 and get 1.
2\sqrt{6}-\frac{\sqrt{3}}{\left(\sqrt{3}\right)^{2}}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Rationalize the denominator of \frac{1}{\sqrt{3}} by multiplying numerator and denominator by \sqrt{3}.
2\sqrt{6}-\frac{\sqrt{3}}{3}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
The square of \sqrt{3} is 3.
\frac{3\times 2\sqrt{6}}{3}-\frac{\sqrt{3}}{3}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 2\sqrt{6} times \frac{3}{3}.
\frac{3\times 2\sqrt{6}-\sqrt{3}}{3}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Since \frac{3\times 2\sqrt{6}}{3} and \frac{\sqrt{3}}{3} have the same denominator, subtract them by subtracting their numerators.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\sqrt{\frac{1}{21}}+\sqrt{6}\right)
Do the multiplications in 3\times 2\sqrt{6}-\sqrt{3}.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\frac{\sqrt{1}}{\sqrt{21}}+\sqrt{6}\right)
Rewrite the square root of the division \sqrt{\frac{1}{21}} as the division of square roots \frac{\sqrt{1}}{\sqrt{21}}.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\frac{1}{\sqrt{21}}+\sqrt{6}\right)
Calculate the square root of 1 and get 1.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\frac{\sqrt{21}}{\left(\sqrt{21}\right)^{2}}+\sqrt{6}\right)
Rationalize the denominator of \frac{1}{\sqrt{21}} by multiplying numerator and denominator by \sqrt{21}.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\frac{\sqrt{21}}{21}+\sqrt{6}\right)
The square of \sqrt{21} is 21.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\left(\frac{\sqrt{21}}{21}+\frac{21\sqrt{6}}{21}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply \sqrt{6} times \frac{21}{21}.
\frac{6\sqrt{6}-\sqrt{3}}{3}-3\times \frac{\sqrt{21}+21\sqrt{6}}{21}
Since \frac{\sqrt{21}}{21} and \frac{21\sqrt{6}}{21} have the same denominator, add them by adding their numerators.
\frac{6\sqrt{6}-\sqrt{3}}{3}-\frac{\sqrt{21}+21\sqrt{6}}{7}
Cancel out 21, the greatest common factor in 3 and 21.
\frac{7\left(6\sqrt{6}-\sqrt{3}\right)}{21}-\frac{3\left(\sqrt{21}+21\sqrt{6}\right)}{21}
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 3 and 7 is 21. Multiply \frac{6\sqrt{6}-\sqrt{3}}{3} times \frac{7}{7}. Multiply \frac{\sqrt{21}+21\sqrt{6}}{7} times \frac{3}{3}.
\frac{7\left(6\sqrt{6}-\sqrt{3}\right)-3\left(\sqrt{21}+21\sqrt{6}\right)}{21}
Since \frac{7\left(6\sqrt{6}-\sqrt{3}\right)}{21} and \frac{3\left(\sqrt{21}+21\sqrt{6}\right)}{21} have the same denominator, subtract them by subtracting their numerators.
\frac{42\sqrt{6}-7\sqrt{3}-3\sqrt{21}-63\sqrt{6}}{21}
Do the multiplications in 7\left(6\sqrt{6}-\sqrt{3}\right)-3\left(\sqrt{21}+21\sqrt{6}\right).
\frac{-21\sqrt{6}-7\sqrt{3}-3\sqrt{21}}{21}
Do the calculations in 42\sqrt{6}-7\sqrt{3}-3\sqrt{21}-63\sqrt{6}.
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}