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n\left(n-3\right)=2n
Multiply both sides of the equation by 2.
n^{2}-3n=2n
Use the distributive property to multiply n by n-3.
n^{2}-3n-2n=0
Subtract 2n from both sides.
n^{2}-5n=0
Combine -3n and -2n to get -5n.
n\left(n-5\right)=0
Factor out n.
n=0 n=5
To find equation solutions, solve n=0 and n-5=0.
n\left(n-3\right)=2n
Multiply both sides of the equation by 2.
n^{2}-3n=2n
Use the distributive property to multiply n by n-3.
n^{2}-3n-2n=0
Subtract 2n from both sides.
n^{2}-5n=0
Combine -3n and -2n to get -5n.
n=\frac{-\left(-5\right)±\sqrt{\left(-5\right)^{2}}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -5 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
n=\frac{-\left(-5\right)±5}{2}
Take the square root of \left(-5\right)^{2}.
n=\frac{5±5}{2}
The opposite of -5 is 5.
n=\frac{10}{2}
Now solve the equation n=\frac{5±5}{2} when ± is plus. Add 5 to 5.
n=5
Divide 10 by 2.
n=\frac{0}{2}
Now solve the equation n=\frac{5±5}{2} when ± is minus. Subtract 5 from 5.
n=0
Divide 0 by 2.
n=5 n=0
The equation is now solved.
n\left(n-3\right)=2n
Multiply both sides of the equation by 2.
n^{2}-3n=2n
Use the distributive property to multiply n by n-3.
n^{2}-3n-2n=0
Subtract 2n from both sides.
n^{2}-5n=0
Combine -3n and -2n to get -5n.
n^{2}-5n+\left(-\frac{5}{2}\right)^{2}=\left(-\frac{5}{2}\right)^{2}
Divide -5, the coefficient of the x term, by 2 to get -\frac{5}{2}. Then add the square of -\frac{5}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
n^{2}-5n+\frac{25}{4}=\frac{25}{4}
Square -\frac{5}{2} by squaring both the numerator and the denominator of the fraction.
\left(n-\frac{5}{2}\right)^{2}=\frac{25}{4}
Factor n^{2}-5n+\frac{25}{4}. 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(n-\frac{5}{2}\right)^{2}}=\sqrt{\frac{25}{4}}
Take the square root of both sides of the equation.
n-\frac{5}{2}=\frac{5}{2} n-\frac{5}{2}=-\frac{5}{2}
Simplify.
n=5 n=0
Add \frac{5}{2} to both sides of the equation.