Evaluate
-4n\left(n-3m\right)
Expand
12mn-4n^{2}
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\left(-3\right)^{2}m^{2}-\left(-3m+2n\right)^{2}
Expand \left(-3m\right)^{2}.
9m^{2}-\left(-3m+2n\right)^{2}
Calculate -3 to the power of 2 and get 9.
9m^{2}-\left(9m^{2}-12mn+4n^{2}\right)
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(-3m+2n\right)^{2}.
9m^{2}-9m^{2}+12mn-4n^{2}
To find the opposite of 9m^{2}-12mn+4n^{2}, find the opposite of each term.
12mn-4n^{2}
Combine 9m^{2} and -9m^{2} to get 0.
\left(-3\right)^{2}m^{2}-\left(-3m+2n\right)^{2}
Expand \left(-3m\right)^{2}.
9m^{2}-\left(-3m+2n\right)^{2}
Calculate -3 to the power of 2 and get 9.
9m^{2}-\left(9m^{2}-12mn+4n^{2}\right)
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(-3m+2n\right)^{2}.
9m^{2}-9m^{2}+12mn-4n^{2}
To find the opposite of 9m^{2}-12mn+4n^{2}, find the opposite of each term.
12mn-4n^{2}
Combine 9m^{2} and -9m^{2} to get 0.
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}