Evaluate
-\frac{3\sqrt{5}}{2}+4\approx 0.645898034
Factor
\frac{8 - 3 \sqrt{5}}{2} = 0.6458980337503153
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\frac{\left(\frac{-3+\sqrt{5}}{2}-\frac{3\times 2}{2}\right)\times \frac{-3+\sqrt{5}}{2}}{2}
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{2}{2}.
\frac{\frac{-3+\sqrt{5}-3\times 2}{2}\times \frac{-3+\sqrt{5}}{2}}{2}
Since \frac{-3+\sqrt{5}}{2} and \frac{3\times 2}{2} have the same denominator, subtract them by subtracting their numerators.
\frac{\frac{-3+\sqrt{5}-6}{2}\times \frac{-3+\sqrt{5}}{2}}{2}
Do the multiplications in -3+\sqrt{5}-3\times 2.
\frac{\frac{-9+\sqrt{5}}{2}\times \frac{-3+\sqrt{5}}{2}}{2}
Do the calculations in -3+\sqrt{5}-6.
\frac{\frac{\left(-9+\sqrt{5}\right)\left(-3+\sqrt{5}\right)}{2\times 2}}{2}
Multiply \frac{-9+\sqrt{5}}{2} times \frac{-3+\sqrt{5}}{2} by multiplying numerator times numerator and denominator times denominator.
\frac{\left(-9+\sqrt{5}\right)\left(-3+\sqrt{5}\right)}{2\times 2\times 2}
Express \frac{\frac{\left(-9+\sqrt{5}\right)\left(-3+\sqrt{5}\right)}{2\times 2}}{2} as a single fraction.
\frac{\left(-9+\sqrt{5}\right)\left(-3+\sqrt{5}\right)}{4\times 2}
Multiply 2 and 2 to get 4.
\frac{\left(-9+\sqrt{5}\right)\left(-3+\sqrt{5}\right)}{8}
Multiply 4 and 2 to get 8.
\frac{27-9\sqrt{5}-3\sqrt{5}+\left(\sqrt{5}\right)^{2}}{8}
Apply the distributive property by multiplying each term of -9+\sqrt{5} by each term of -3+\sqrt{5}.
\frac{27-12\sqrt{5}+\left(\sqrt{5}\right)^{2}}{8}
Combine -9\sqrt{5} and -3\sqrt{5} to get -12\sqrt{5}.
\frac{27-12\sqrt{5}+5}{8}
The square of \sqrt{5} is 5.
\frac{32-12\sqrt{5}}{8}
Add 27 and 5 to get 32.
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}