Solve for x
x=4
Graph
Share
Copied to clipboard
\frac{\left(3+\frac{8}{x}\right)x}{2}=10
Variable x cannot be equal to 0 since division by zero is not defined. Divide 3+\frac{8}{x} by \frac{2}{x} by multiplying 3+\frac{8}{x} by the reciprocal of \frac{2}{x}.
\frac{\left(\frac{3x}{x}+\frac{8}{x}\right)x}{2}=10
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{x}{x}.
\frac{\frac{3x+8}{x}x}{2}=10
Since \frac{3x}{x} and \frac{8}{x} have the same denominator, add them by adding their numerators.
\frac{\frac{\left(3x+8\right)x}{x}}{2}=10
Express \frac{3x+8}{x}x as a single fraction.
\frac{\frac{3x^{2}+8x}{x}}{2}=10
Use the distributive property to multiply 3x+8 by x.
\frac{3x^{2}+8x}{x}=10\times 2
Multiply both sides by 2.
3x^{2}+8x=10\times 2x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x.
3x^{2}+8x=20x
Multiply 10 and 2 to get 20.
3x^{2}+8x-20x=0
Subtract 20x from both sides.
3x^{2}-12x=0
Combine 8x and -20x to get -12x.
x\left(3x-12\right)=0
Factor out x.
x=0 x=4
To find equation solutions, solve x=0 and 3x-12=0.
x=4
Variable x cannot be equal to 0.
\frac{\left(3+\frac{8}{x}\right)x}{2}=10
Variable x cannot be equal to 0 since division by zero is not defined. Divide 3+\frac{8}{x} by \frac{2}{x} by multiplying 3+\frac{8}{x} by the reciprocal of \frac{2}{x}.
\frac{\left(\frac{3x}{x}+\frac{8}{x}\right)x}{2}=10
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{x}{x}.
\frac{\frac{3x+8}{x}x}{2}=10
Since \frac{3x}{x} and \frac{8}{x} have the same denominator, add them by adding their numerators.
\frac{\frac{\left(3x+8\right)x}{x}}{2}=10
Express \frac{3x+8}{x}x as a single fraction.
\frac{\frac{3x^{2}+8x}{x}}{2}=10
Use the distributive property to multiply 3x+8 by x.
\frac{\frac{3x^{2}+8x}{x}}{2}-10=0
Subtract 10 from both sides.
\frac{3x^{2}+8x}{x}-20=0
Multiply both sides of the equation by 2.
3x^{2}+8x+x\left(-20\right)=0
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x.
3x^{2}-12x=0
Combine 8x and x\left(-20\right) to get -12x.
x=\frac{-\left(-12\right)±\sqrt{\left(-12\right)^{2}}}{2\times 3}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3 for a, -12 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-12\right)±12}{2\times 3}
Take the square root of \left(-12\right)^{2}.
x=\frac{12±12}{2\times 3}
The opposite of -12 is 12.
x=\frac{12±12}{6}
Multiply 2 times 3.
x=\frac{24}{6}
Now solve the equation x=\frac{12±12}{6} when ± is plus. Add 12 to 12.
x=4
Divide 24 by 6.
x=\frac{0}{6}
Now solve the equation x=\frac{12±12}{6} when ± is minus. Subtract 12 from 12.
x=0
Divide 0 by 6.
x=4 x=0
The equation is now solved.
x=4
Variable x cannot be equal to 0.
\frac{\left(3+\frac{8}{x}\right)x}{2}=10
Variable x cannot be equal to 0 since division by zero is not defined. Divide 3+\frac{8}{x} by \frac{2}{x} by multiplying 3+\frac{8}{x} by the reciprocal of \frac{2}{x}.
\frac{\left(\frac{3x}{x}+\frac{8}{x}\right)x}{2}=10
To add or subtract expressions, expand them to make their denominators the same. Multiply 3 times \frac{x}{x}.
\frac{\frac{3x+8}{x}x}{2}=10
Since \frac{3x}{x} and \frac{8}{x} have the same denominator, add them by adding their numerators.
\frac{\frac{\left(3x+8\right)x}{x}}{2}=10
Express \frac{3x+8}{x}x as a single fraction.
\frac{\frac{3x^{2}+8x}{x}}{2}=10
Use the distributive property to multiply 3x+8 by x.
\frac{3x^{2}+8x}{x}=10\times 2
Multiply both sides by 2.
3x^{2}+8x=10\times 2x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by x.
3x^{2}+8x=20x
Multiply 10 and 2 to get 20.
3x^{2}+8x-20x=0
Subtract 20x from both sides.
3x^{2}-12x=0
Combine 8x and -20x to get -12x.
\frac{3x^{2}-12x}{3}=\frac{0}{3}
Divide both sides by 3.
x^{2}+\left(-\frac{12}{3}\right)x=\frac{0}{3}
Dividing by 3 undoes the multiplication by 3.
x^{2}-4x=\frac{0}{3}
Divide -12 by 3.
x^{2}-4x=0
Divide 0 by 3.
x^{2}-4x+\left(-2\right)^{2}=\left(-2\right)^{2}
Divide -4, the coefficient of the x term, by 2 to get -2. Then add the square of -2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-4x+4=4
Square -2.
\left(x-2\right)^{2}=4
Factor x^{2}-4x+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-2\right)^{2}}=\sqrt{4}
Take the square root of both sides of the equation.
x-2=2 x-2=-2
Simplify.
x=4 x=0
Add 2 to both sides of the equation.
x=4
Variable x cannot be equal to 0.
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}