Evaluate
\left(x+\left(-2-4i\right)\right)\left(x+\left(-2+4i\right)\right)
Expand
x^{2}-4x+20
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\left(x+\left(-2-4i\right)\right)\left(x-\left(2-4i\right)\right)
Multiply -1 and 2+4i to get -2-4i.
\left(x+\left(-2-4i\right)\right)\left(x+\left(-2+4i\right)\right)
Multiply -1 and 2-4i to get -2+4i.
x^{2}+\left(-2+4i\right)x+\left(-2-4i\right)x+20
Apply the distributive property by multiplying each term of x+\left(-2-4i\right) by each term of x+\left(-2+4i\right).
x^{2}-4x+20
Combine \left(-2+4i\right)x and \left(-2-4i\right)x to get -4x.
\left(x+\left(-2-4i\right)\right)\left(x-\left(2-4i\right)\right)
Multiply -1 and 2+4i to get -2-4i.
\left(x+\left(-2-4i\right)\right)\left(x+\left(-2+4i\right)\right)
Multiply -1 and 2-4i to get -2+4i.
x^{2}+\left(-2+4i\right)x+\left(-2-4i\right)x+20
Apply the distributive property by multiplying each term of x+\left(-2-4i\right) by each term of x+\left(-2+4i\right).
x^{2}-4x+20
Combine \left(-2+4i\right)x and \left(-2-4i\right)x to get -4x.
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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}