Solve for a
a=-5
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2\left(2\times \left(\frac{a}{2}\right)^{3}-a\times \left(\frac{a}{2}\right)^{2}\right)+4a+20=0
Multiply both sides of the equation by 2.
2\left(2\times \frac{a^{3}}{2^{3}}-a\times \left(\frac{a}{2}\right)^{2}\right)+4a+20=0
To raise \frac{a}{2} to a power, raise both numerator and denominator to the power and then divide.
2\left(\frac{2a^{3}}{2^{3}}-a\times \left(\frac{a}{2}\right)^{2}\right)+4a+20=0
Express 2\times \frac{a^{3}}{2^{3}} as a single fraction.
2\left(\frac{a^{3}}{2^{2}}-a\times \left(\frac{a}{2}\right)^{2}\right)+4a+20=0
Cancel out 2 in both numerator and denominator.
2\left(\frac{a^{3}}{2^{2}}-a\times \frac{a^{2}}{2^{2}}\right)+4a+20=0
To raise \frac{a}{2} to a power, raise both numerator and denominator to the power and then divide.
2\left(\frac{a^{3}}{2^{2}}-\frac{aa^{2}}{2^{2}}\right)+4a+20=0
Express a\times \frac{a^{2}}{2^{2}} as a single fraction.
2\left(\frac{a^{3}}{2^{2}}-\frac{a^{3}}{2^{2}}\right)+4a+20=0
To multiply powers of the same base, add their exponents. Add 1 and 2 to get 3.
2\left(\frac{a^{3}}{2^{2}}-\frac{a^{3}}{4}\right)+4a+20=0
Calculate 2 to the power of 2 and get 4.
2\left(\frac{a^{3}}{4}-\frac{a^{3}}{4}\right)+4a+20=0
To add or subtract expressions, expand them to make their denominators the same. Expand 2^{2}.
2\times \frac{a^{3}-a^{3}}{4}+4a+20=0
Since \frac{a^{3}}{4} and \frac{a^{3}}{4} have the same denominator, subtract them by subtracting their numerators.
2\times \frac{0}{4}+4a+20=0
Combine like terms in a^{3}-a^{3}.
\frac{0}{2}+4a+20=0
Cancel out 4, the greatest common factor in 2 and 4.
0+4a+20=0
Zero divided by any non-zero number gives zero.
20+4a=0
Add 0 and 20 to get 20.
4a=-20
Subtract 20 from both sides. Anything subtracted from zero gives its negation.
a=\frac{-20}{4}
Divide both sides by 4.
a=-5
Divide -20 by 4 to get -5.
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}