Evaluate
\frac{4\sqrt{5}}{5}\approx 1.788854382
Quiz
Arithmetic
5 problems similar to:
- \frac{ 1 }{ 2 } \left( - \frac{ 8 \sqrt{ 5 } }{ 5 } -4 \right) -2
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-\frac{1}{2}\left(-\frac{8\sqrt{5}}{5}-\frac{4\times 5}{5}\right)-2
To add or subtract expressions, expand them to make their denominators the same. Multiply 4 times \frac{5}{5}.
-\frac{1}{2}\times \frac{-8\sqrt{5}-4\times 5}{5}-2
Since -\frac{8\sqrt{5}}{5} and \frac{4\times 5}{5} have the same denominator, subtract them by subtracting their numerators.
-\frac{1}{2}\times \frac{-8\sqrt{5}-20}{5}-2
Do the multiplications in -8\sqrt{5}-4\times 5.
\frac{-\left(-8\sqrt{5}-20\right)}{2\times 5}-2
Multiply -\frac{1}{2} times \frac{-8\sqrt{5}-20}{5} by multiplying numerator times numerator and denominator times denominator.
\frac{-\left(-8\sqrt{5}-20\right)}{2\times 5}-\frac{2\times 2\times 5}{2\times 5}
To add or subtract expressions, expand them to make their denominators the same. Multiply 2 times \frac{2\times 5}{2\times 5}.
\frac{-\left(-8\sqrt{5}-20\right)-2\times 2\times 5}{2\times 5}
Since \frac{-\left(-8\sqrt{5}-20\right)}{2\times 5} and \frac{2\times 2\times 5}{2\times 5} have the same denominator, subtract them by subtracting their numerators.
\frac{8\sqrt{5}+20-20}{2\times 5}
Do the multiplications in -\left(-8\sqrt{5}-20\right)-2\times 2\times 5.
\frac{8\sqrt{5}}{2\times 5}
Do the calculations in 8\sqrt{5}+20-20.
\frac{4\sqrt{5}}{5}
Cancel out 2 in both numerator and denominator.
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}