Evaluate
\frac{z-4}{z+7}
Expand
\frac{z-4}{z+7}
Share
Copied to clipboard
\frac{\left(z^{2}-9z+20\right)\left(z+3\right)}{\left(z+3\right)\left(z^{2}+2z-35\right)}
Divide \frac{z^{2}-9z+20}{z+3} by \frac{z^{2}+2z-35}{z+3} by multiplying \frac{z^{2}-9z+20}{z+3} by the reciprocal of \frac{z^{2}+2z-35}{z+3}.
\frac{z^{2}-9z+20}{z^{2}+2z-35}
Cancel out z+3 in both numerator and denominator.
\frac{\left(z-5\right)\left(z-4\right)}{\left(z-5\right)\left(z+7\right)}
Factor the expressions that are not already factored.
\frac{z-4}{z+7}
Cancel out z-5 in both numerator and denominator.
\frac{\left(z^{2}-9z+20\right)\left(z+3\right)}{\left(z+3\right)\left(z^{2}+2z-35\right)}
Divide \frac{z^{2}-9z+20}{z+3} by \frac{z^{2}+2z-35}{z+3} by multiplying \frac{z^{2}-9z+20}{z+3} by the reciprocal of \frac{z^{2}+2z-35}{z+3}.
\frac{z^{2}-9z+20}{z^{2}+2z-35}
Cancel out z+3 in both numerator and denominator.
\frac{\left(z-5\right)\left(z-4\right)}{\left(z-5\right)\left(z+7\right)}
Factor the expressions that are not already factored.
\frac{z-4}{z+7}
Cancel out z-5 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}