Factor
f\left(2f+5\right)
Evaluate
f\left(2f+5\right)
Share
Copied to clipboard
f\left(2f+5\right)
Factor out f.
2f^{2}+5f=0
Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.
f=\frac{-5±\sqrt{5^{2}}}{2\times 2}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
f=\frac{-5±5}{2\times 2}
Take the square root of 5^{2}.
f=\frac{-5±5}{4}
Multiply 2 times 2.
f=\frac{0}{4}
Now solve the equation f=\frac{-5±5}{4} when ± is plus. Add -5 to 5.
f=0
Divide 0 by 4.
f=-\frac{10}{4}
Now solve the equation f=\frac{-5±5}{4} when ± is minus. Subtract 5 from -5.
f=-\frac{5}{2}
Reduce the fraction \frac{-10}{4} to lowest terms by extracting and canceling out 2.
2f^{2}+5f=2f\left(f-\left(-\frac{5}{2}\right)\right)
Factor the original expression using ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Substitute 0 for x_{1} and -\frac{5}{2} for x_{2}.
2f^{2}+5f=2f\left(f+\frac{5}{2}\right)
Simplify all the expressions of the form p-\left(-q\right) to p+q.
2f^{2}+5f=2f\times \frac{2f+5}{2}
Add \frac{5}{2} to f by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
2f^{2}+5f=f\left(2f+5\right)
Cancel out 2, the greatest common factor in 2 and 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}