Evaluate
-\frac{y^{2}}{4}+9x^{2}
Expand
-\frac{y^{2}}{4}+9x^{2}
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\left(\frac{2\times 3x}{2}+\frac{y}{2}\right)\left(-\frac{y}{2}+3x\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3x times \frac{2}{2}.
\frac{2\times 3x+y}{2}\left(-\frac{y}{2}+3x\right)
Since \frac{2\times 3x}{2} and \frac{y}{2} have the same denominator, add them by adding their numerators.
\frac{6x+y}{2}\left(-\frac{y}{2}+3x\right)
Do the multiplications in 2\times 3x+y.
\frac{6x+y}{2}\left(-\frac{y}{2}+\frac{2\times 3x}{2}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3x times \frac{2}{2}.
\frac{6x+y}{2}\times \frac{-y+2\times 3x}{2}
Since -\frac{y}{2} and \frac{2\times 3x}{2} have the same denominator, add them by adding their numerators.
\frac{6x+y}{2}\times \frac{-y+6x}{2}
Do the multiplications in -y+2\times 3x.
\frac{\left(6x+y\right)\left(-y+6x\right)}{2\times 2}
Multiply \frac{6x+y}{2} times \frac{-y+6x}{2} by multiplying numerator times numerator and denominator times denominator.
\frac{\left(6x+y\right)\left(-y+6x\right)}{4}
Multiply 2 and 2 to get 4.
\frac{-6xy+36x^{2}-y^{2}+6yx}{4}
Apply the distributive property by multiplying each term of 6x+y by each term of -y+6x.
\frac{36x^{2}-y^{2}}{4}
Combine -6xy and 6yx to get 0.
\left(\frac{2\times 3x}{2}+\frac{y}{2}\right)\left(-\frac{y}{2}+3x\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3x times \frac{2}{2}.
\frac{2\times 3x+y}{2}\left(-\frac{y}{2}+3x\right)
Since \frac{2\times 3x}{2} and \frac{y}{2} have the same denominator, add them by adding their numerators.
\frac{6x+y}{2}\left(-\frac{y}{2}+3x\right)
Do the multiplications in 2\times 3x+y.
\frac{6x+y}{2}\left(-\frac{y}{2}+\frac{2\times 3x}{2}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3x times \frac{2}{2}.
\frac{6x+y}{2}\times \frac{-y+2\times 3x}{2}
Since -\frac{y}{2} and \frac{2\times 3x}{2} have the same denominator, add them by adding their numerators.
\frac{6x+y}{2}\times \frac{-y+6x}{2}
Do the multiplications in -y+2\times 3x.
\frac{\left(6x+y\right)\left(-y+6x\right)}{2\times 2}
Multiply \frac{6x+y}{2} times \frac{-y+6x}{2} by multiplying numerator times numerator and denominator times denominator.
\frac{\left(6x+y\right)\left(-y+6x\right)}{4}
Multiply 2 and 2 to get 4.
\frac{-6xy+36x^{2}-y^{2}+6yx}{4}
Apply the distributive property by multiplying each term of 6x+y by each term of -y+6x.
\frac{36x^{2}-y^{2}}{4}
Combine -6xy and 6yx 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}