Solve for x
x=1
x=4
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-\frac{1}{2}x\times 2x+2x\times \frac{5}{2}=2\times 2
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2,x.
-xx+2x\times \frac{5}{2}=2\times 2
Cancel out 2 and 2.
-x^{2}+2x\times \frac{5}{2}=2\times 2
Multiply x and x to get x^{2}.
-x^{2}+5x=2\times 2
Cancel out 2 and 2.
-x^{2}+5x=4
Multiply 2 and 2 to get 4.
-x^{2}+5x-4=0
Subtract 4 from both sides.
x=\frac{-5±\sqrt{5^{2}-4\left(-1\right)\left(-4\right)}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 5 for b, and -4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-5±\sqrt{25-4\left(-1\right)\left(-4\right)}}{2\left(-1\right)}
Square 5.
x=\frac{-5±\sqrt{25+4\left(-4\right)}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-5±\sqrt{25-16}}{2\left(-1\right)}
Multiply 4 times -4.
x=\frac{-5±\sqrt{9}}{2\left(-1\right)}
Add 25 to -16.
x=\frac{-5±3}{2\left(-1\right)}
Take the square root of 9.
x=\frac{-5±3}{-2}
Multiply 2 times -1.
x=-\frac{2}{-2}
Now solve the equation x=\frac{-5±3}{-2} when ± is plus. Add -5 to 3.
x=1
Divide -2 by -2.
x=-\frac{8}{-2}
Now solve the equation x=\frac{-5±3}{-2} when ± is minus. Subtract 3 from -5.
x=4
Divide -8 by -2.
x=1 x=4
The equation is now solved.
-\frac{1}{2}x\times 2x+2x\times \frac{5}{2}=2\times 2
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2,x.
-xx+2x\times \frac{5}{2}=2\times 2
Cancel out 2 and 2.
-x^{2}+2x\times \frac{5}{2}=2\times 2
Multiply x and x to get x^{2}.
-x^{2}+5x=2\times 2
Cancel out 2 and 2.
-x^{2}+5x=4
Multiply 2 and 2 to get 4.
\frac{-x^{2}+5x}{-1}=\frac{4}{-1}
Divide both sides by -1.
x^{2}+\frac{5}{-1}x=\frac{4}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-5x=\frac{4}{-1}
Divide 5 by -1.
x^{2}-5x=-4
Divide 4 by -1.
x^{2}-5x+\left(-\frac{5}{2}\right)^{2}=-4+\left(-\frac{5}{2}\right)^{2}
Divide -5, the coefficient of the x term, by 2 to get -\frac{5}{2}. Then add the square of -\frac{5}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-5x+\frac{25}{4}=-4+\frac{25}{4}
Square -\frac{5}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-5x+\frac{25}{4}=\frac{9}{4}
Add -4 to \frac{25}{4}.
\left(x-\frac{5}{2}\right)^{2}=\frac{9}{4}
Factor x^{2}-5x+\frac{25}{4}. 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{5}{2}\right)^{2}}=\sqrt{\frac{9}{4}}
Take the square root of both sides of the equation.
x-\frac{5}{2}=\frac{3}{2} x-\frac{5}{2}=-\frac{3}{2}
Simplify.
x=4 x=1
Add \frac{5}{2} to both sides of the equation.
Examples
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y = 3x + 4
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Matrix
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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
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