Solve for x
x=\frac{\sqrt{5}-1}{2}\approx 0.618033989
x=\frac{-\sqrt{5}-1}{2}\approx -1.618033989
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x^{2}-5x+6-5\left(x-3\right)\left(x^{2}-4\right)^{-1}=0
Variable x cannot be equal to 3 since division by zero is not defined. Multiply both sides of the equation by x-3.
x^{2}-5x+6+\left(-5x+15\right)\left(x^{2}-4\right)^{-1}=0
Use the distributive property to multiply -5 by x-3.
x^{2}-5x+6-5x\left(x^{2}-4\right)^{-1}+15\left(x^{2}-4\right)^{-1}=0
Use the distributive property to multiply -5x+15 by \left(x^{2}-4\right)^{-1}.
x^{2}-5x+6-5\times \frac{1}{x^{2}-4}x+15\times \frac{1}{x^{2}-4}=0
Reorder the terms.
\left(x-2\right)\left(x+2\right)x^{2}-5x\left(x-2\right)\left(x+2\right)+\left(x-2\right)\left(x+2\right)\times 6-5x+15\times 1=0
Variable x cannot be equal to any of the values -2,2 since division by zero is not defined. Multiply both sides of the equation by \left(x-2\right)\left(x+2\right).
\left(x-2\right)\left(x+2\right)x^{2}-5x\left(x-2\right)\left(x+2\right)+\left(x-2\right)\left(x+2\right)\times 6-5x+15=0
Do the multiplications.
\left(x^{2}-4\right)x^{2}-5x\left(x-2\right)\left(x+2\right)+\left(x-2\right)\left(x+2\right)\times 6-5x+15=0
Consider \left(x-2\right)\left(x+2\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 2.
x^{4}-4x^{2}-5x\left(x-2\right)\left(x+2\right)+\left(x-2\right)\left(x+2\right)\times 6-5x+15=0
Use the distributive property to multiply x^{2}-4 by x^{2}.
x^{4}-4x^{2}+\left(-5x^{2}+10x\right)\left(x+2\right)+\left(x-2\right)\left(x+2\right)\times 6-5x+15=0
Use the distributive property to multiply -5x by x-2.
x^{4}-4x^{2}-5x^{3}+20x+\left(x-2\right)\left(x+2\right)\times 6-5x+15=0
Use the distributive property to multiply -5x^{2}+10x by x+2 and combine like terms.
x^{4}-4x^{2}-5x^{3}+20x+\left(x^{2}-4\right)\times 6-5x+15=0
Use the distributive property to multiply x-2 by x+2 and combine like terms.
x^{4}-4x^{2}-5x^{3}+20x+6x^{2}-24-5x+15=0
Use the distributive property to multiply x^{2}-4 by 6.
x^{4}+2x^{2}-5x^{3}+20x-24-5x+15=0
Combine -4x^{2} and 6x^{2} to get 2x^{2}.
x^{4}+2x^{2}-5x^{3}+15x-24+15=0
Combine 20x and -5x to get 15x.
x^{4}+2x^{2}-5x^{3}+15x-9=0
Add -24 and 15 to get -9.
x^{4}-5x^{3}+2x^{2}+15x-9=0
Rearrange the equation to put it in standard form. Place the terms in order from highest to lowest power.
±9,±3,±1
By Rational Root Theorem, all rational roots of a polynomial are in the form \frac{p}{q}, where p divides the constant term -9 and q divides the leading coefficient 1. List all candidates \frac{p}{q}.
x=3
Find one such root by trying out all the integer values, starting from the smallest by absolute value. If no integer roots are found, try out fractions.
x^{3}-2x^{2}-4x+3=0
By Factor theorem, x-k is a factor of the polynomial for each root k. Divide x^{4}-5x^{3}+2x^{2}+15x-9 by x-3 to get x^{3}-2x^{2}-4x+3. Solve the equation where the result equals to 0.
±3,±1
By Rational Root Theorem, all rational roots of a polynomial are in the form \frac{p}{q}, where p divides the constant term 3 and q divides the leading coefficient 1. List all candidates \frac{p}{q}.
x=3
Find one such root by trying out all the integer values, starting from the smallest by absolute value. If no integer roots are found, try out fractions.
x^{2}+x-1=0
By Factor theorem, x-k is a factor of the polynomial for each root k. Divide x^{3}-2x^{2}-4x+3 by x-3 to get x^{2}+x-1. Solve the equation where the result equals to 0.
x=\frac{-1±\sqrt{1^{2}-4\times 1\left(-1\right)}}{2}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Substitute 1 for a, 1 for b, and -1 for c in the quadratic formula.
x=\frac{-1±\sqrt{5}}{2}
Do the calculations.
x=\frac{-\sqrt{5}-1}{2} x=\frac{\sqrt{5}-1}{2}
Solve the equation x^{2}+x-1=0 when ± is plus and when ± is minus.
x\in \emptyset
Remove the values that the variable cannot be equal to.
x=3 x=\frac{-\sqrt{5}-1}{2} x=\frac{\sqrt{5}-1}{2}
List all found solutions.
x=\frac{\sqrt{5}-1}{2} x=\frac{-\sqrt{5}-1}{2}
Variable x cannot be equal to 3.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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Linear equation
y = 3x + 4
Arithmetic
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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
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