Solve for x
x=1
x=105
Graph
Share
Copied to clipboard
5520-212x+2x^{2}=6\times 885
Use the distributive property to multiply 92-2x by 60-x and combine like terms.
5520-212x+2x^{2}=5310
Multiply 6 and 885 to get 5310.
5520-212x+2x^{2}-5310=0
Subtract 5310 from both sides.
210-212x+2x^{2}=0
Subtract 5310 from 5520 to get 210.
2x^{2}-212x+210=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(-212\right)±\sqrt{\left(-212\right)^{2}-4\times 2\times 210}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, -212 for b, and 210 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-212\right)±\sqrt{44944-4\times 2\times 210}}{2\times 2}
Square -212.
x=\frac{-\left(-212\right)±\sqrt{44944-8\times 210}}{2\times 2}
Multiply -4 times 2.
x=\frac{-\left(-212\right)±\sqrt{44944-1680}}{2\times 2}
Multiply -8 times 210.
x=\frac{-\left(-212\right)±\sqrt{43264}}{2\times 2}
Add 44944 to -1680.
x=\frac{-\left(-212\right)±208}{2\times 2}
Take the square root of 43264.
x=\frac{212±208}{2\times 2}
The opposite of -212 is 212.
x=\frac{212±208}{4}
Multiply 2 times 2.
x=\frac{420}{4}
Now solve the equation x=\frac{212±208}{4} when ± is plus. Add 212 to 208.
x=105
Divide 420 by 4.
x=\frac{4}{4}
Now solve the equation x=\frac{212±208}{4} when ± is minus. Subtract 208 from 212.
x=1
Divide 4 by 4.
x=105 x=1
The equation is now solved.
5520-212x+2x^{2}=6\times 885
Use the distributive property to multiply 92-2x by 60-x and combine like terms.
5520-212x+2x^{2}=5310
Multiply 6 and 885 to get 5310.
-212x+2x^{2}=5310-5520
Subtract 5520 from both sides.
-212x+2x^{2}=-210
Subtract 5520 from 5310 to get -210.
2x^{2}-212x=-210
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}-212x}{2}=-\frac{210}{2}
Divide both sides by 2.
x^{2}+\left(-\frac{212}{2}\right)x=-\frac{210}{2}
Dividing by 2 undoes the multiplication by 2.
x^{2}-106x=-\frac{210}{2}
Divide -212 by 2.
x^{2}-106x=-105
Divide -210 by 2.
x^{2}-106x+\left(-53\right)^{2}=-105+\left(-53\right)^{2}
Divide -106, the coefficient of the x term, by 2 to get -53. Then add the square of -53 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-106x+2809=-105+2809
Square -53.
x^{2}-106x+2809=2704
Add -105 to 2809.
\left(x-53\right)^{2}=2704
Factor x^{2}-106x+2809. 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-53\right)^{2}}=\sqrt{2704}
Take the square root of both sides of the equation.
x-53=52 x-53=-52
Simplify.
x=105 x=1
Add 53 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}