Evaluate
\frac{2}{7}\approx 0.285714286
Factor
\frac{2}{7} = 0.2857142857142857
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3-\left(\frac{21}{7}-\frac{2}{7}\right)
Convert 3 to fraction \frac{21}{7}.
3-\frac{21-2}{7}
Since \frac{21}{7} and \frac{2}{7} have the same denominator, subtract them by subtracting their numerators.
3-\frac{19}{7}
Subtract 2 from 21 to get 19.
\frac{21}{7}-\frac{19}{7}
Convert 3 to fraction \frac{21}{7}.
\frac{21-19}{7}
Since \frac{21}{7} and \frac{19}{7} have the same denominator, subtract them by subtracting their numerators.
\frac{2}{7}
Subtract 19 from 21 to get 2.
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}