Evaluate
\frac{\left(b-5\right)\left(b+3\right)}{4}
Expand
\frac{b^{2}}{4}-\frac{b}{2}-\frac{15}{4}
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\frac{\left(b^{2}-2b-15\right)\left(4b+10\right)}{\left(8b+20\right)\times 2}
Divide \frac{b^{2}-2b-15}{8b+20} by \frac{2}{4b+10} by multiplying \frac{b^{2}-2b-15}{8b+20} by the reciprocal of \frac{2}{4b+10}.
\frac{2\left(b-5\right)\left(b+3\right)\left(2b+5\right)}{2\times 4\left(2b+5\right)}
Factor the expressions that are not already factored.
\frac{\left(b-5\right)\left(b+3\right)}{4}
Cancel out 2\left(2b+5\right) in both numerator and denominator.
\frac{b^{2}-2b-15}{4}
Expand the expression.
\frac{\left(b^{2}-2b-15\right)\left(4b+10\right)}{\left(8b+20\right)\times 2}
Divide \frac{b^{2}-2b-15}{8b+20} by \frac{2}{4b+10} by multiplying \frac{b^{2}-2b-15}{8b+20} by the reciprocal of \frac{2}{4b+10}.
\frac{2\left(b-5\right)\left(b+3\right)\left(2b+5\right)}{2\times 4\left(2b+5\right)}
Factor the expressions that are not already factored.
\frac{\left(b-5\right)\left(b+3\right)}{4}
Cancel out 2\left(2b+5\right) in both numerator and denominator.
\frac{b^{2}-2b-15}{4}
Expand the expression.
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}