Solve for x
x=2
x=3
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\left(x-5\right)\times 8-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Variable x cannot be equal to any of the values -5,5 since division by zero is not defined. Multiply both sides of the equation by \left(x-5\right)\left(x+5\right), the least common multiple of x+5,x^{2}-25,x-5.
8x-40-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by 8.
8x-72=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Subtract 32 from -40 to get -72.
8x-72=\left(x^{2}-25\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by x+5 and combine like terms.
8x-72=2x^{2}-50-\left(x+5\right)\times 2
Use the distributive property to multiply x^{2}-25 by 2.
8x-72=2x^{2}-50-\left(2x+10\right)
Use the distributive property to multiply x+5 by 2.
8x-72=2x^{2}-50-2x-10
To find the opposite of 2x+10, find the opposite of each term.
8x-72=2x^{2}-60-2x
Subtract 10 from -50 to get -60.
8x-72-2x^{2}=-60-2x
Subtract 2x^{2} from both sides.
8x-72-2x^{2}-\left(-60\right)=-2x
Subtract -60 from both sides.
8x-72-2x^{2}+60=-2x
The opposite of -60 is 60.
8x-72-2x^{2}+60+2x=0
Add 2x to both sides.
8x-12-2x^{2}+2x=0
Add -72 and 60 to get -12.
10x-12-2x^{2}=0
Combine 8x and 2x to get 10x.
5x-6-x^{2}=0
Divide both sides by 2.
-x^{2}+5x-6=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=5 ab=-\left(-6\right)=6
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx-6. To find a and b, set up a system to be solved.
1,6 2,3
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 6.
1+6=7 2+3=5
Calculate the sum for each pair.
a=3 b=2
The solution is the pair that gives sum 5.
\left(-x^{2}+3x\right)+\left(2x-6\right)
Rewrite -x^{2}+5x-6 as \left(-x^{2}+3x\right)+\left(2x-6\right).
-x\left(x-3\right)+2\left(x-3\right)
Factor out -x in the first and 2 in the second group.
\left(x-3\right)\left(-x+2\right)
Factor out common term x-3 by using distributive property.
x=3 x=2
To find equation solutions, solve x-3=0 and -x+2=0.
\left(x-5\right)\times 8-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Variable x cannot be equal to any of the values -5,5 since division by zero is not defined. Multiply both sides of the equation by \left(x-5\right)\left(x+5\right), the least common multiple of x+5,x^{2}-25,x-5.
8x-40-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by 8.
8x-72=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Subtract 32 from -40 to get -72.
8x-72=\left(x^{2}-25\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by x+5 and combine like terms.
8x-72=2x^{2}-50-\left(x+5\right)\times 2
Use the distributive property to multiply x^{2}-25 by 2.
8x-72=2x^{2}-50-\left(2x+10\right)
Use the distributive property to multiply x+5 by 2.
8x-72=2x^{2}-50-2x-10
To find the opposite of 2x+10, find the opposite of each term.
8x-72=2x^{2}-60-2x
Subtract 10 from -50 to get -60.
8x-72-2x^{2}=-60-2x
Subtract 2x^{2} from both sides.
8x-72-2x^{2}-\left(-60\right)=-2x
Subtract -60 from both sides.
8x-72-2x^{2}+60=-2x
The opposite of -60 is 60.
8x-72-2x^{2}+60+2x=0
Add 2x to both sides.
8x-12-2x^{2}+2x=0
Add -72 and 60 to get -12.
10x-12-2x^{2}=0
Combine 8x and 2x to get 10x.
-2x^{2}+10x-12=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{-10±\sqrt{10^{2}-4\left(-2\right)\left(-12\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 10 for b, and -12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-10±\sqrt{100-4\left(-2\right)\left(-12\right)}}{2\left(-2\right)}
Square 10.
x=\frac{-10±\sqrt{100+8\left(-12\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-10±\sqrt{100-96}}{2\left(-2\right)}
Multiply 8 times -12.
x=\frac{-10±\sqrt{4}}{2\left(-2\right)}
Add 100 to -96.
x=\frac{-10±2}{2\left(-2\right)}
Take the square root of 4.
x=\frac{-10±2}{-4}
Multiply 2 times -2.
x=-\frac{8}{-4}
Now solve the equation x=\frac{-10±2}{-4} when ± is plus. Add -10 to 2.
x=2
Divide -8 by -4.
x=-\frac{12}{-4}
Now solve the equation x=\frac{-10±2}{-4} when ± is minus. Subtract 2 from -10.
x=3
Divide -12 by -4.
x=2 x=3
The equation is now solved.
\left(x-5\right)\times 8-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Variable x cannot be equal to any of the values -5,5 since division by zero is not defined. Multiply both sides of the equation by \left(x-5\right)\left(x+5\right), the least common multiple of x+5,x^{2}-25,x-5.
8x-40-32=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by 8.
8x-72=\left(x-5\right)\left(x+5\right)\times 2-\left(x+5\right)\times 2
Subtract 32 from -40 to get -72.
8x-72=\left(x^{2}-25\right)\times 2-\left(x+5\right)\times 2
Use the distributive property to multiply x-5 by x+5 and combine like terms.
8x-72=2x^{2}-50-\left(x+5\right)\times 2
Use the distributive property to multiply x^{2}-25 by 2.
8x-72=2x^{2}-50-\left(2x+10\right)
Use the distributive property to multiply x+5 by 2.
8x-72=2x^{2}-50-2x-10
To find the opposite of 2x+10, find the opposite of each term.
8x-72=2x^{2}-60-2x
Subtract 10 from -50 to get -60.
8x-72-2x^{2}=-60-2x
Subtract 2x^{2} from both sides.
8x-72-2x^{2}+2x=-60
Add 2x to both sides.
10x-72-2x^{2}=-60
Combine 8x and 2x to get 10x.
10x-2x^{2}=-60+72
Add 72 to both sides.
10x-2x^{2}=12
Add -60 and 72 to get 12.
-2x^{2}+10x=12
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.
\frac{-2x^{2}+10x}{-2}=\frac{12}{-2}
Divide both sides by -2.
x^{2}+\frac{10}{-2}x=\frac{12}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-5x=\frac{12}{-2}
Divide 10 by -2.
x^{2}-5x=-6
Divide 12 by -2.
x^{2}-5x+\left(-\frac{5}{2}\right)^{2}=-6+\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}=-6+\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{1}{4}
Add -6 to \frac{25}{4}.
\left(x-\frac{5}{2}\right)^{2}=\frac{1}{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{1}{4}}
Take the square root of both sides of the equation.
x-\frac{5}{2}=\frac{1}{2} x-\frac{5}{2}=-\frac{1}{2}
Simplify.
x=3 x=2
Add \frac{5}{2} to both sides of the equation.
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}