Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

3x^{2}=\left(8-x\right)\times 2x
Variable x cannot be equal to 8 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-8\right)^{2}, the least common multiple of \left(8-x\right)^{2},24-3x.
3x^{2}=\left(16-2x\right)x
Use the distributive property to multiply 8-x by 2.
3x^{2}=16x-2x^{2}
Use the distributive property to multiply 16-2x by x.
3x^{2}-16x=-2x^{2}
Subtract 16x from both sides.
3x^{2}-16x+2x^{2}=0
Add 2x^{2} to both sides.
5x^{2}-16x=0
Combine 3x^{2} and 2x^{2} to get 5x^{2}.
x\left(5x-16\right)=0
Factor out x.
x=0 x=\frac{16}{5}
To find equation solutions, solve x=0 and 5x-16=0.
3x^{2}=\left(8-x\right)\times 2x
Variable x cannot be equal to 8 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-8\right)^{2}, the least common multiple of \left(8-x\right)^{2},24-3x.
3x^{2}=\left(16-2x\right)x
Use the distributive property to multiply 8-x by 2.
3x^{2}=16x-2x^{2}
Use the distributive property to multiply 16-2x by x.
3x^{2}-16x=-2x^{2}
Subtract 16x from both sides.
3x^{2}-16x+2x^{2}=0
Add 2x^{2} to both sides.
5x^{2}-16x=0
Combine 3x^{2} and 2x^{2} to get 5x^{2}.
x=\frac{-\left(-16\right)±\sqrt{\left(-16\right)^{2}}}{2\times 5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, -16 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-16\right)±16}{2\times 5}
Take the square root of \left(-16\right)^{2}.
x=\frac{16±16}{2\times 5}
The opposite of -16 is 16.
x=\frac{16±16}{10}
Multiply 2 times 5.
x=\frac{32}{10}
Now solve the equation x=\frac{16±16}{10} when ± is plus. Add 16 to 16.
x=\frac{16}{5}
Reduce the fraction \frac{32}{10} to lowest terms by extracting and canceling out 2.
x=\frac{0}{10}
Now solve the equation x=\frac{16±16}{10} when ± is minus. Subtract 16 from 16.
x=0
Divide 0 by 10.
x=\frac{16}{5} x=0
The equation is now solved.
3x^{2}=\left(8-x\right)\times 2x
Variable x cannot be equal to 8 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-8\right)^{2}, the least common multiple of \left(8-x\right)^{2},24-3x.
3x^{2}=\left(16-2x\right)x
Use the distributive property to multiply 8-x by 2.
3x^{2}=16x-2x^{2}
Use the distributive property to multiply 16-2x by x.
3x^{2}-16x=-2x^{2}
Subtract 16x from both sides.
3x^{2}-16x+2x^{2}=0
Add 2x^{2} to both sides.
5x^{2}-16x=0
Combine 3x^{2} and 2x^{2} to get 5x^{2}.
\frac{5x^{2}-16x}{5}=\frac{0}{5}
Divide both sides by 5.
x^{2}-\frac{16}{5}x=\frac{0}{5}
Dividing by 5 undoes the multiplication by 5.
x^{2}-\frac{16}{5}x=0
Divide 0 by 5.
x^{2}-\frac{16}{5}x+\left(-\frac{8}{5}\right)^{2}=\left(-\frac{8}{5}\right)^{2}
Divide -\frac{16}{5}, the coefficient of the x term, by 2 to get -\frac{8}{5}. Then add the square of -\frac{8}{5} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{16}{5}x+\frac{64}{25}=\frac{64}{25}
Square -\frac{8}{5} by squaring both the numerator and the denominator of the fraction.
\left(x-\frac{8}{5}\right)^{2}=\frac{64}{25}
Factor x^{2}-\frac{16}{5}x+\frac{64}{25}. 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{8}{5}\right)^{2}}=\sqrt{\frac{64}{25}}
Take the square root of both sides of the equation.
x-\frac{8}{5}=\frac{8}{5} x-\frac{8}{5}=-\frac{8}{5}
Simplify.
x=\frac{16}{5} x=0
Add \frac{8}{5} to both sides of the equation.