Solve for x
x=-5
x=6
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\left(x-4\right)\left(x+4\right)=x+14
Variable x cannot be equal to any of the values -6,4 since division by zero is not defined. Multiply both sides of the equation by \left(x-4\right)\left(x+6\right), the least common multiple of x+6,x^{2}+2x-24.
x^{2}-16=x+14
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16-x=14
Subtract x from both sides.
x^{2}-16-x-14=0
Subtract 14 from both sides.
x^{2}-30-x=0
Subtract 14 from -16 to get -30.
x^{2}-x-30=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=-1 ab=-30
To solve the equation, factor x^{2}-x-30 using formula x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). To find a and b, set up a system to be solved.
1,-30 2,-15 3,-10 5,-6
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -30.
1-30=-29 2-15=-13 3-10=-7 5-6=-1
Calculate the sum for each pair.
a=-6 b=5
The solution is the pair that gives sum -1.
\left(x-6\right)\left(x+5\right)
Rewrite factored expression \left(x+a\right)\left(x+b\right) using the obtained values.
x=6 x=-5
To find equation solutions, solve x-6=0 and x+5=0.
\left(x-4\right)\left(x+4\right)=x+14
Variable x cannot be equal to any of the values -6,4 since division by zero is not defined. Multiply both sides of the equation by \left(x-4\right)\left(x+6\right), the least common multiple of x+6,x^{2}+2x-24.
x^{2}-16=x+14
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16-x=14
Subtract x from both sides.
x^{2}-16-x-14=0
Subtract 14 from both sides.
x^{2}-30-x=0
Subtract 14 from -16 to get -30.
x^{2}-x-30=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=-1 ab=1\left(-30\right)=-30
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx-30. To find a and b, set up a system to be solved.
1,-30 2,-15 3,-10 5,-6
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -30.
1-30=-29 2-15=-13 3-10=-7 5-6=-1
Calculate the sum for each pair.
a=-6 b=5
The solution is the pair that gives sum -1.
\left(x^{2}-6x\right)+\left(5x-30\right)
Rewrite x^{2}-x-30 as \left(x^{2}-6x\right)+\left(5x-30\right).
x\left(x-6\right)+5\left(x-6\right)
Factor out x in the first and 5 in the second group.
\left(x-6\right)\left(x+5\right)
Factor out common term x-6 by using distributive property.
x=6 x=-5
To find equation solutions, solve x-6=0 and x+5=0.
\left(x-4\right)\left(x+4\right)=x+14
Variable x cannot be equal to any of the values -6,4 since division by zero is not defined. Multiply both sides of the equation by \left(x-4\right)\left(x+6\right), the least common multiple of x+6,x^{2}+2x-24.
x^{2}-16=x+14
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16-x=14
Subtract x from both sides.
x^{2}-16-x-14=0
Subtract 14 from both sides.
x^{2}-30-x=0
Subtract 14 from -16 to get -30.
x^{2}-x-30=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(-1\right)±\sqrt{1-4\left(-30\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -1 for b, and -30 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-1\right)±\sqrt{1+120}}{2}
Multiply -4 times -30.
x=\frac{-\left(-1\right)±\sqrt{121}}{2}
Add 1 to 120.
x=\frac{-\left(-1\right)±11}{2}
Take the square root of 121.
x=\frac{1±11}{2}
The opposite of -1 is 1.
x=\frac{12}{2}
Now solve the equation x=\frac{1±11}{2} when ± is plus. Add 1 to 11.
x=6
Divide 12 by 2.
x=-\frac{10}{2}
Now solve the equation x=\frac{1±11}{2} when ± is minus. Subtract 11 from 1.
x=-5
Divide -10 by 2.
x=6 x=-5
The equation is now solved.
\left(x-4\right)\left(x+4\right)=x+14
Variable x cannot be equal to any of the values -6,4 since division by zero is not defined. Multiply both sides of the equation by \left(x-4\right)\left(x+6\right), the least common multiple of x+6,x^{2}+2x-24.
x^{2}-16=x+14
Consider \left(x-4\right)\left(x+4\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 4.
x^{2}-16-x=14
Subtract x from both sides.
x^{2}-x=14+16
Add 16 to both sides.
x^{2}-x=30
Add 14 and 16 to get 30.
x^{2}-x+\left(-\frac{1}{2}\right)^{2}=30+\left(-\frac{1}{2}\right)^{2}
Divide -1, the coefficient of the x term, by 2 to get -\frac{1}{2}. Then add the square of -\frac{1}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-x+\frac{1}{4}=30+\frac{1}{4}
Square -\frac{1}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-x+\frac{1}{4}=\frac{121}{4}
Add 30 to \frac{1}{4}.
\left(x-\frac{1}{2}\right)^{2}=\frac{121}{4}
Factor x^{2}-x+\frac{1}{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{1}{2}\right)^{2}}=\sqrt{\frac{121}{4}}
Take the square root of both sides of the equation.
x-\frac{1}{2}=\frac{11}{2} x-\frac{1}{2}=-\frac{11}{2}
Simplify.
x=6 x=-5
Add \frac{1}{2} to both sides of the equation.
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
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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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