Evaluate
5-\sqrt{7}\approx 2.354248689
Share
Copied to clipboard
\frac{5\sqrt{2}-\sqrt{14}}{\sqrt{2}}
Factor 50=5^{2}\times 2. Rewrite the square root of the product \sqrt{5^{2}\times 2} as the product of square roots \sqrt{5^{2}}\sqrt{2}. Take the square root of 5^{2}.
\frac{\left(5\sqrt{2}-\sqrt{14}\right)\sqrt{2}}{\left(\sqrt{2}\right)^{2}}
Rationalize the denominator of \frac{5\sqrt{2}-\sqrt{14}}{\sqrt{2}} by multiplying numerator and denominator by \sqrt{2}.
\frac{\left(5\sqrt{2}-\sqrt{14}\right)\sqrt{2}}{2}
The square of \sqrt{2} is 2.
\frac{5\left(\sqrt{2}\right)^{2}-\sqrt{14}\sqrt{2}}{2}
Use the distributive property to multiply 5\sqrt{2}-\sqrt{14} by \sqrt{2}.
\frac{5\times 2-\sqrt{14}\sqrt{2}}{2}
The square of \sqrt{2} is 2.
\frac{10-\sqrt{14}\sqrt{2}}{2}
Multiply 5 and 2 to get 10.
\frac{10-\sqrt{2}\sqrt{7}\sqrt{2}}{2}
Factor 14=2\times 7. Rewrite the square root of the product \sqrt{2\times 7} as the product of square roots \sqrt{2}\sqrt{7}.
\frac{10-2\sqrt{7}}{2}
Multiply \sqrt{2} and \sqrt{2} to get 2.
5-\sqrt{7}
Divide each term of 10-2\sqrt{7} by 2 to get 5-\sqrt{7}.
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}