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-9+16x+9+16x^{2}-24x=0
Subtract 12 from 3 to get -9.
16x+16x^{2}-24x=0
Add -9 and 9 to get 0.
-8x+16x^{2}=0
Combine 16x and -24x to get -8x.
x\left(-8+16x\right)=0
Factor out x.
x=0 x=\frac{1}{2}
To find equation solutions, solve x=0 and -8+16x=0.
-9+16x+9+16x^{2}-24x=0
Subtract 12 from 3 to get -9.
16x+16x^{2}-24x=0
Add -9 and 9 to get 0.
-8x+16x^{2}=0
Combine 16x and -24x to get -8x.
16x^{2}-8x=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(-8\right)±\sqrt{\left(-8\right)^{2}}}{2\times 16}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 16 for a, -8 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-8\right)±8}{2\times 16}
Take the square root of \left(-8\right)^{2}.
x=\frac{8±8}{2\times 16}
The opposite of -8 is 8.
x=\frac{8±8}{32}
Multiply 2 times 16.
x=\frac{16}{32}
Now solve the equation x=\frac{8±8}{32} when ± is plus. Add 8 to 8.
x=\frac{1}{2}
Reduce the fraction \frac{16}{32} to lowest terms by extracting and canceling out 16.
x=\frac{0}{32}
Now solve the equation x=\frac{8±8}{32} when ± is minus. Subtract 8 from 8.
x=0
Divide 0 by 32.
x=\frac{1}{2} x=0
The equation is now solved.
-9+16x+9+16x^{2}-24x=0
Subtract 12 from 3 to get -9.
16x+16x^{2}-24x=0
Add -9 and 9 to get 0.
-8x+16x^{2}=0
Combine 16x and -24x to get -8x.
16x^{2}-8x=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}-8x}{16}=\frac{0}{16}
Divide both sides by 16.
x^{2}+\left(-\frac{8}{16}\right)x=\frac{0}{16}
Dividing by 16 undoes the multiplication by 16.
x^{2}-\frac{1}{2}x=\frac{0}{16}
Reduce the fraction \frac{-8}{16} to lowest terms by extracting and canceling out 8.
x^{2}-\frac{1}{2}x=0
Divide 0 by 16.
x^{2}-\frac{1}{2}x+\left(-\frac{1}{4}\right)^{2}=\left(-\frac{1}{4}\right)^{2}
Divide -\frac{1}{2}, the coefficient of the x term, by 2 to get -\frac{1}{4}. Then add the square of -\frac{1}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{1}{2}x+\frac{1}{16}=\frac{1}{16}
Square -\frac{1}{4} by squaring both the numerator and the denominator of the fraction.
\left(x-\frac{1}{4}\right)^{2}=\frac{1}{16}
Factor x^{2}-\frac{1}{2}x+\frac{1}{16}. 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}{4}\right)^{2}}=\sqrt{\frac{1}{16}}
Take the square root of both sides of the equation.
x-\frac{1}{4}=\frac{1}{4} x-\frac{1}{4}=-\frac{1}{4}
Simplify.
x=\frac{1}{2} x=0
Add \frac{1}{4} to both sides of the equation.