Evaluate
\frac{x^{2}}{4}-9
Expand
\frac{x^{2}}{4}-9
Graph
Share
Copied to clipboard
\left(\frac{x}{2}-\frac{3\times 2}{2}\right)\left(\frac{x}{2}+3\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{2}{2}.
\frac{x-3\times 2}{2}\left(\frac{x}{2}+3\right)
Since \frac{x}{2} and \frac{3\times 2}{2} have the same denominator, subtract them by subtracting their numerators.
\frac{x-6}{2}\left(\frac{x}{2}+3\right)
Do the multiplications in x-3\times 2.
\frac{x-6}{2}\left(\frac{x}{2}+\frac{3\times 2}{2}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{2}{2}.
\frac{x-6}{2}\times \frac{x+3\times 2}{2}
Since \frac{x}{2} and \frac{3\times 2}{2} have the same denominator, add them by adding their numerators.
\frac{x-6}{2}\times \frac{x+6}{2}
Do the multiplications in x+3\times 2.
\frac{\left(x-6\right)\left(x+6\right)}{2\times 2}
Multiply \frac{x-6}{2} times \frac{x+6}{2} by multiplying numerator times numerator and denominator times denominator.
\frac{\left(x-6\right)\left(x+6\right)}{4}
Multiply 2 and 2 to get 4.
\frac{x^{2}-6^{2}}{4}
Consider \left(x-6\right)\left(x+6\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.
\frac{x^{2}-36}{4}
Calculate 6 to the power of 2 and get 36.
\left(\frac{x}{2}-\frac{3\times 2}{2}\right)\left(\frac{x}{2}+3\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{2}{2}.
\frac{x-3\times 2}{2}\left(\frac{x}{2}+3\right)
Since \frac{x}{2} and \frac{3\times 2}{2} have the same denominator, subtract them by subtracting their numerators.
\frac{x-6}{2}\left(\frac{x}{2}+3\right)
Do the multiplications in x-3\times 2.
\frac{x-6}{2}\left(\frac{x}{2}+\frac{3\times 2}{2}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{2}{2}.
\frac{x-6}{2}\times \frac{x+3\times 2}{2}
Since \frac{x}{2} and \frac{3\times 2}{2} have the same denominator, add them by adding their numerators.
\frac{x-6}{2}\times \frac{x+6}{2}
Do the multiplications in x+3\times 2.
\frac{\left(x-6\right)\left(x+6\right)}{2\times 2}
Multiply \frac{x-6}{2} times \frac{x+6}{2} by multiplying numerator times numerator and denominator times denominator.
\frac{\left(x-6\right)\left(x+6\right)}{4}
Multiply 2 and 2 to get 4.
\frac{x^{2}-6^{2}}{4}
Consider \left(x-6\right)\left(x+6\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.
\frac{x^{2}-36}{4}
Calculate 6 to the power of 2 and get 36.
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}