Solve for x
x=6
x=0
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96x-16x^{2}+256=256
Swap sides so that all variable terms are on the left hand side.
96x-16x^{2}+256-256=0
Subtract 256 from both sides.
96x-16x^{2}=0
Subtract 256 from 256 to get 0.
x\left(96-16x\right)=0
Factor out x.
x=0 x=6
To find equation solutions, solve x=0 and 96-16x=0.
96x-16x^{2}+256=256
Swap sides so that all variable terms are on the left hand side.
96x-16x^{2}+256-256=0
Subtract 256 from both sides.
96x-16x^{2}=0
Subtract 256 from 256 to get 0.
-16x^{2}+96x=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{-96±\sqrt{96^{2}}}{2\left(-16\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -16 for a, 96 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-96±96}{2\left(-16\right)}
Take the square root of 96^{2}.
x=\frac{-96±96}{-32}
Multiply 2 times -16.
x=\frac{0}{-32}
Now solve the equation x=\frac{-96±96}{-32} when ± is plus. Add -96 to 96.
x=0
Divide 0 by -32.
x=-\frac{192}{-32}
Now solve the equation x=\frac{-96±96}{-32} when ± is minus. Subtract 96 from -96.
x=6
Divide -192 by -32.
x=0 x=6
The equation is now solved.
96x-16x^{2}+256=256
Swap sides so that all variable terms are on the left hand side.
96x-16x^{2}=256-256
Subtract 256 from both sides.
96x-16x^{2}=0
Subtract 256 from 256 to get 0.
-16x^{2}+96x=0
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{-16x^{2}+96x}{-16}=\frac{0}{-16}
Divide both sides by -16.
x^{2}+\frac{96}{-16}x=\frac{0}{-16}
Dividing by -16 undoes the multiplication by -16.
x^{2}-6x=\frac{0}{-16}
Divide 96 by -16.
x^{2}-6x=0
Divide 0 by -16.
x^{2}-6x+\left(-3\right)^{2}=\left(-3\right)^{2}
Divide -6, the coefficient of the x term, by 2 to get -3. Then add the square of -3 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-6x+9=9
Square -3.
\left(x-3\right)^{2}=9
Factor x^{2}-6x+9. 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-3\right)^{2}}=\sqrt{9}
Take the square root of both sides of the equation.
x-3=3 x-3=-3
Simplify.
x=6 x=0
Add 3 to both sides of the equation.
Examples
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{ 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}