Solve for x
x=\frac{7}{9}\approx 0.777777778
x=0
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9x^{2}\times 1=5x+2x
Multiply x and x to get x^{2}.
9x^{2}=5x+2x
Multiply 9 and 1 to get 9.
9x^{2}=7x
Combine 5x and 2x to get 7x.
9x^{2}-7x=0
Subtract 7x from both sides.
x\left(9x-7\right)=0
Factor out x.
x=0 x=\frac{7}{9}
To find equation solutions, solve x=0 and 9x-7=0.
9x^{2}\times 1=5x+2x
Multiply x and x to get x^{2}.
9x^{2}=5x+2x
Multiply 9 and 1 to get 9.
9x^{2}=7x
Combine 5x and 2x to get 7x.
9x^{2}-7x=0
Subtract 7x from both sides.
x=\frac{-\left(-7\right)±\sqrt{\left(-7\right)^{2}}}{2\times 9}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 9 for a, -7 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-7\right)±7}{2\times 9}
Take the square root of \left(-7\right)^{2}.
x=\frac{7±7}{2\times 9}
The opposite of -7 is 7.
x=\frac{7±7}{18}
Multiply 2 times 9.
x=\frac{14}{18}
Now solve the equation x=\frac{7±7}{18} when ± is plus. Add 7 to 7.
x=\frac{7}{9}
Reduce the fraction \frac{14}{18} to lowest terms by extracting and canceling out 2.
x=\frac{0}{18}
Now solve the equation x=\frac{7±7}{18} when ± is minus. Subtract 7 from 7.
x=0
Divide 0 by 18.
x=\frac{7}{9} x=0
The equation is now solved.
9x^{2}\times 1=5x+2x
Multiply x and x to get x^{2}.
9x^{2}=5x+2x
Multiply 9 and 1 to get 9.
9x^{2}=7x
Combine 5x and 2x to get 7x.
9x^{2}-7x=0
Subtract 7x from both sides.
\frac{9x^{2}-7x}{9}=\frac{0}{9}
Divide both sides by 9.
x^{2}-\frac{7}{9}x=\frac{0}{9}
Dividing by 9 undoes the multiplication by 9.
x^{2}-\frac{7}{9}x=0
Divide 0 by 9.
x^{2}-\frac{7}{9}x+\left(-\frac{7}{18}\right)^{2}=\left(-\frac{7}{18}\right)^{2}
Divide -\frac{7}{9}, the coefficient of the x term, by 2 to get -\frac{7}{18}. Then add the square of -\frac{7}{18} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{7}{9}x+\frac{49}{324}=\frac{49}{324}
Square -\frac{7}{18} by squaring both the numerator and the denominator of the fraction.
\left(x-\frac{7}{18}\right)^{2}=\frac{49}{324}
Factor x^{2}-\frac{7}{9}x+\frac{49}{324}. 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{7}{18}\right)^{2}}=\sqrt{\frac{49}{324}}
Take the square root of both sides of the equation.
x-\frac{7}{18}=\frac{7}{18} x-\frac{7}{18}=-\frac{7}{18}
Simplify.
x=\frac{7}{9} x=0
Add \frac{7}{18} to both sides of the equation.
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Simultaneous equation
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Differentiation
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Integration
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Limits
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