Solve for X
X=\frac{1}{2}=0.5
X=1
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2X^{2}-3X+1=0
Divide both sides by 2.
a+b=-3 ab=2\times 1=2
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 2X^{2}+aX+bX+1. To find a and b, set up a system to be solved.
a=-2 b=-1
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. The only such pair is the system solution.
\left(2X^{2}-2X\right)+\left(-X+1\right)
Rewrite 2X^{2}-3X+1 as \left(2X^{2}-2X\right)+\left(-X+1\right).
2X\left(X-1\right)-\left(X-1\right)
Factor out 2X in the first and -1 in the second group.
\left(X-1\right)\left(2X-1\right)
Factor out common term X-1 by using distributive property.
X=1 X=\frac{1}{2}
To find equation solutions, solve X-1=0 and 2X-1=0.
4X^{2}-6X+2=0
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)±\sqrt{\left(-6\right)^{2}-4\times 4\times 2}}{2\times 4}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, -6 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
X=\frac{-\left(-6\right)±\sqrt{36-4\times 4\times 2}}{2\times 4}
Square -6.
X=\frac{-\left(-6\right)±\sqrt{36-16\times 2}}{2\times 4}
Multiply -4 times 4.
X=\frac{-\left(-6\right)±\sqrt{36-32}}{2\times 4}
Multiply -16 times 2.
X=\frac{-\left(-6\right)±\sqrt{4}}{2\times 4}
Add 36 to -32.
X=\frac{-\left(-6\right)±2}{2\times 4}
Take the square root of 4.
X=\frac{6±2}{2\times 4}
The opposite of -6 is 6.
X=\frac{6±2}{8}
Multiply 2 times 4.
X=\frac{8}{8}
Now solve the equation X=\frac{6±2}{8} when ± is plus. Add 6 to 2.
X=1
Divide 8 by 8.
X=\frac{4}{8}
Now solve the equation X=\frac{6±2}{8} when ± is minus. Subtract 2 from 6.
X=\frac{1}{2}
Reduce the fraction \frac{4}{8} to lowest terms by extracting and canceling out 4.
X=1 X=\frac{1}{2}
The equation is now solved.
4X^{2}-6X+2=0
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
4X^{2}-6X+2-2=-2
Subtract 2 from both sides of the equation.
4X^{2}-6X=-2
Subtracting 2 from itself leaves 0.
\frac{4X^{2}-6X}{4}=-\frac{2}{4}
Divide both sides by 4.
X^{2}+\left(-\frac{6}{4}\right)X=-\frac{2}{4}
Dividing by 4 undoes the multiplication by 4.
X^{2}-\frac{3}{2}X=-\frac{2}{4}
Reduce the fraction \frac{-6}{4} to lowest terms by extracting and canceling out 2.
X^{2}-\frac{3}{2}X=-\frac{1}{2}
Reduce the fraction \frac{-2}{4} to lowest terms by extracting and canceling out 2.
X^{2}-\frac{3}{2}X+\left(-\frac{3}{4}\right)^{2}=-\frac{1}{2}+\left(-\frac{3}{4}\right)^{2}
Divide -\frac{3}{2}, the coefficient of the x term, by 2 to get -\frac{3}{4}. Then add the square of -\frac{3}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
X^{2}-\frac{3}{2}X+\frac{9}{16}=-\frac{1}{2}+\frac{9}{16}
Square -\frac{3}{4} by squaring both the numerator and the denominator of the fraction.
X^{2}-\frac{3}{2}X+\frac{9}{16}=\frac{1}{16}
Add -\frac{1}{2} to \frac{9}{16} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(X-\frac{3}{4}\right)^{2}=\frac{1}{16}
Factor X^{2}-\frac{3}{2}X+\frac{9}{16}. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(X-\frac{3}{4}\right)^{2}}=\sqrt{\frac{1}{16}}
Take the square root of both sides of the equation.
X-\frac{3}{4}=\frac{1}{4} X-\frac{3}{4}=-\frac{1}{4}
Simplify.
X=1 X=\frac{1}{2}
Add \frac{3}{4} to both sides of the equation.
x ^ 2 -\frac{3}{2}x +\frac{1}{2} = 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 4
r + s = \frac{3}{2} rs = \frac{1}{2}
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 = \frac{3}{4} - u s = \frac{3}{4} + u
Two numbers r and s sum up to \frac{3}{2} exactly when the average of the two numbers is \frac{1}{2}*\frac{3}{2} = \frac{3}{4}. 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>
(\frac{3}{4} - u) (\frac{3}{4} + u) = \frac{1}{2}
To solve for unknown quantity u, substitute these in the product equation rs = \frac{1}{2}
\frac{9}{16} - u^2 = \frac{1}{2}
Simplify by expanding (a -b) (a + b) = a^2 – b^2
-u^2 = \frac{1}{2}-\frac{9}{16} = -\frac{1}{16}
Simplify the expression by subtracting \frac{9}{16} on both sides
u^2 = \frac{1}{16} u = \pm\sqrt{\frac{1}{16}} = \pm \frac{1}{4}
Simplify the expression by multiplying -1 on both sides and take the square root to obtain the value of unknown variable u
r =\frac{3}{4} - \frac{1}{4} = 0.500 s = \frac{3}{4} + \frac{1}{4} = 1
The factors r and s are the solutions to the quadratic equation. Substitute the value of u to compute the r and s.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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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}