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v\left(-v+1\right)=2\left(-6\right)
Variable v cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2v, the least common multiple of 2,v.
v\left(-v\right)+v=2\left(-6\right)
Use the distributive property to multiply v by -v+1.
v\left(-v\right)+v=-12
Multiply 2 and -6 to get -12.
v\left(-v\right)+v+12=0
Add 12 to both sides.
v^{2}\left(-1\right)+v+12=0
Multiply v and v to get v^{2}.
-v^{2}+v+12=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.
v=\frac{-1±\sqrt{1^{2}-4\left(-1\right)\times 12}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 1 for b, and 12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
v=\frac{-1±\sqrt{1-4\left(-1\right)\times 12}}{2\left(-1\right)}
Square 1.
v=\frac{-1±\sqrt{1+4\times 12}}{2\left(-1\right)}
Multiply -4 times -1.
v=\frac{-1±\sqrt{1+48}}{2\left(-1\right)}
Multiply 4 times 12.
v=\frac{-1±\sqrt{49}}{2\left(-1\right)}
Add 1 to 48.
v=\frac{-1±7}{2\left(-1\right)}
Take the square root of 49.
v=\frac{-1±7}{-2}
Multiply 2 times -1.
v=\frac{6}{-2}
Now solve the equation v=\frac{-1±7}{-2} when ± is plus. Add -1 to 7.
v=-3
Divide 6 by -2.
v=-\frac{8}{-2}
Now solve the equation v=\frac{-1±7}{-2} when ± is minus. Subtract 7 from -1.
v=4
Divide -8 by -2.
v=-3 v=4
The equation is now solved.
v\left(-v+1\right)=2\left(-6\right)
Variable v cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2v, the least common multiple of 2,v.
v\left(-v\right)+v=2\left(-6\right)
Use the distributive property to multiply v by -v+1.
v\left(-v\right)+v=-12
Multiply 2 and -6 to get -12.
v^{2}\left(-1\right)+v=-12
Multiply v and v to get v^{2}.
-v^{2}+v=-12
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{-v^{2}+v}{-1}=-\frac{12}{-1}
Divide both sides by -1.
v^{2}+\frac{1}{-1}v=-\frac{12}{-1}
Dividing by -1 undoes the multiplication by -1.
v^{2}-v=-\frac{12}{-1}
Divide 1 by -1.
v^{2}-v=12
Divide -12 by -1.
v^{2}-v+\left(-\frac{1}{2}\right)^{2}=12+\left(-\frac{1}{2}\right)^{2}
Divide -1, the coefficient of the x term, by 2 to get -\frac{1}{2}. Then add the square of -\frac{1}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
v^{2}-v+\frac{1}{4}=12+\frac{1}{4}
Square -\frac{1}{2} by squaring both the numerator and the denominator of the fraction.
v^{2}-v+\frac{1}{4}=\frac{49}{4}
Add 12 to \frac{1}{4}.
\left(v-\frac{1}{2}\right)^{2}=\frac{49}{4}
Factor v^{2}-v+\frac{1}{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(v-\frac{1}{2}\right)^{2}}=\sqrt{\frac{49}{4}}
Take the square root of both sides of the equation.
v-\frac{1}{2}=\frac{7}{2} v-\frac{1}{2}=-\frac{7}{2}
Simplify.
v=4 v=-3
Add \frac{1}{2} to both sides of the equation.