Evaluate
\frac{3x^{2}-x-1}{x^{2}-4}
Expand
\frac{3x^{2}-x-1}{x^{2}-4}
Graph
Share
Copied to clipboard
\frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of x-2 and x+2 is \left(x-2\right)\left(x+2\right). Multiply \frac{x}{x-2} times \frac{x+2}{x+2}. Multiply \frac{2x+1}{x+2} times \frac{x-2}{x-2}.
\frac{x\left(x+2\right)+\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Since \frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)} and \frac{\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)} have the same denominator, add them by adding their numerators.
\frac{x^{2}+2x+2x^{2}-4x+x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Do the multiplications in x\left(x+2\right)+\left(2x+1\right)\left(x-2\right).
\frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Combine like terms in x^{2}+2x+2x^{2}-4x+x-2.
\frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{\left(x-2\right)\left(x+2\right)}
Factor x^{2}-4.
\frac{3x^{2}-x-2+1}{\left(x-2\right)\left(x+2\right)}
Since \frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)} and \frac{1}{\left(x-2\right)\left(x+2\right)} have the same denominator, add them by adding their numerators.
\frac{3x^{2}-x-1}{\left(x-2\right)\left(x+2\right)}
Combine like terms in 3x^{2}-x-2+1.
\frac{3x^{2}-x-1}{x^{2}-4}
Expand \left(x-2\right)\left(x+2\right).
\frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
To add or subtract expressions, expand them to make their denominators the same. Least common multiple of x-2 and x+2 is \left(x-2\right)\left(x+2\right). Multiply \frac{x}{x-2} times \frac{x+2}{x+2}. Multiply \frac{2x+1}{x+2} times \frac{x-2}{x-2}.
\frac{x\left(x+2\right)+\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Since \frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)} and \frac{\left(2x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)} have the same denominator, add them by adding their numerators.
\frac{x^{2}+2x+2x^{2}-4x+x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Do the multiplications in x\left(x+2\right)+\left(2x+1\right)\left(x-2\right).
\frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{x^{2}-4}
Combine like terms in x^{2}+2x+2x^{2}-4x+x-2.
\frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)}+\frac{1}{\left(x-2\right)\left(x+2\right)}
Factor x^{2}-4.
\frac{3x^{2}-x-2+1}{\left(x-2\right)\left(x+2\right)}
Since \frac{3x^{2}-x-2}{\left(x-2\right)\left(x+2\right)} and \frac{1}{\left(x-2\right)\left(x+2\right)} have the same denominator, add them by adding their numerators.
\frac{3x^{2}-x-1}{\left(x-2\right)\left(x+2\right)}
Combine like terms in 3x^{2}-x-2+1.
\frac{3x^{2}-x-1}{x^{2}-4}
Expand \left(x-2\right)\left(x+2\right).
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}