Evaluate
3x\left(x-2\right)
Factor
3x\left(x-2\right)
Graph
Share
Copied to clipboard
3x^{2}-6x
Anything plus zero gives itself.
x ^ 2 -2x +0 = 0
Quadratic equations such as this one can be solved by a new direct factoring method that does not require guess work. To use the direct factoring method, the equation must be in the form x^2+Bx+C=0.This is achieved by dividing both sides of the equation by 3
r + s = 2 rs = 0
Let r and s be the factors for the quadratic equation such that x^2+Bx+C=(x−r)(x−s) where sum of factors (r+s)=−B and the product of factors rs = C
r = 1 - u s = 1 + u
Two numbers r and s sum up to 2 exactly when the average of the two numbers is \frac{1}{2}*2 = 1. You can also see that the midpoint of r and s corresponds to the axis of symmetry of the parabola represented by the quadratic equation y=x^2+Bx+C. The values of r and s are equidistant from the center by an unknown quantity u. Express r and s with respect to variable u. <div style='padding: 8px'><img src='https://opalmath.azureedge.net/customsolver/quadraticgraph.png' style='width: 100%;max-width: 700px' /></div>
(1 - u) (1 + u) = 0
To solve for unknown quantity u, substitute these in the product equation rs = 0
1 - u^2 = 0
Simplify by expanding (a -b) (a + b) = a^2 – b^2
-u^2 = 0-1 = -1
Simplify the expression by subtracting 1 on both sides
u^2 = 1 u = \pm\sqrt{1} = \pm 1
Simplify the expression by multiplying -1 on both sides and take the square root to obtain the value of unknown variable u
r =1 - 1 = 0 s = 1 + 1 = 2
The factors r and s are the solutions to the quadratic equation. Substitute the value of u to compute the r and s.
3\left(x^{2}-2x\right)
Factor out 3.
x\left(x-2\right)
Consider x^{2}-2x. Factor out x.
3x\left(x-2\right)
Rewrite the complete factored expression.
3x^{2}-6x=0
Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.
x=\frac{-\left(-6\right)±\sqrt{\left(-6\right)^{2}}}{2\times 3}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-\left(-6\right)±6}{2\times 3}
Take the square root of \left(-6\right)^{2}.
x=\frac{6±6}{2\times 3}
The opposite of -6 is 6.
x=\frac{6±6}{6}
Multiply 2 times 3.
x=\frac{12}{6}
Now solve the equation x=\frac{6±6}{6} when ± is plus. Add 6 to 6.
x=2
Divide 12 by 6.
x=\frac{0}{6}
Now solve the equation x=\frac{6±6}{6} when ± is minus. Subtract 6 from 6.
x=0
Divide 0 by 6.
3x^{2}-6x=3\left(x-2\right)x
Factor the original expression using ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Substitute 2 for x_{1} and 0 for x_{2}.
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}