Solve for v
v=-8
v=6
Quiz
Quadratic Equation
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\frac { 6 } { v ^ { 2 } - 4 v } = \frac { 1 } { 8 - v }
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\left(v-8\right)\times 6=-v\left(-4+v\right)
Variable v cannot be equal to any of the values 0,4,8 since division by zero is not defined. Multiply both sides of the equation by v\left(v-8\right)\left(v-4\right), the least common multiple of v^{2}-4v,8-v.
6v-48=-v\left(-4+v\right)
Use the distributive property to multiply v-8 by 6.
6v-48=4v-v^{2}
Use the distributive property to multiply -v by -4+v.
6v-48-4v=-v^{2}
Subtract 4v from both sides.
2v-48=-v^{2}
Combine 6v and -4v to get 2v.
2v-48+v^{2}=0
Add v^{2} to both sides.
v^{2}+2v-48=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=2 ab=-48
To solve the equation, factor v^{2}+2v-48 using formula v^{2}+\left(a+b\right)v+ab=\left(v+a\right)\left(v+b\right). To find a and b, set up a system to be solved.
-1,48 -2,24 -3,16 -4,12 -6,8
Since ab is negative, a and b have the opposite signs. Since a+b is positive, the positive number has greater absolute value than the negative. List all such integer pairs that give product -48.
-1+48=47 -2+24=22 -3+16=13 -4+12=8 -6+8=2
Calculate the sum for each pair.
a=-6 b=8
The solution is the pair that gives sum 2.
\left(v-6\right)\left(v+8\right)
Rewrite factored expression \left(v+a\right)\left(v+b\right) using the obtained values.
v=6 v=-8
To find equation solutions, solve v-6=0 and v+8=0.
\left(v-8\right)\times 6=-v\left(-4+v\right)
Variable v cannot be equal to any of the values 0,4,8 since division by zero is not defined. Multiply both sides of the equation by v\left(v-8\right)\left(v-4\right), the least common multiple of v^{2}-4v,8-v.
6v-48=-v\left(-4+v\right)
Use the distributive property to multiply v-8 by 6.
6v-48=4v-v^{2}
Use the distributive property to multiply -v by -4+v.
6v-48-4v=-v^{2}
Subtract 4v from both sides.
2v-48=-v^{2}
Combine 6v and -4v to get 2v.
2v-48+v^{2}=0
Add v^{2} to both sides.
v^{2}+2v-48=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=2 ab=1\left(-48\right)=-48
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as v^{2}+av+bv-48. To find a and b, set up a system to be solved.
-1,48 -2,24 -3,16 -4,12 -6,8
Since ab is negative, a and b have the opposite signs. Since a+b is positive, the positive number has greater absolute value than the negative. List all such integer pairs that give product -48.
-1+48=47 -2+24=22 -3+16=13 -4+12=8 -6+8=2
Calculate the sum for each pair.
a=-6 b=8
The solution is the pair that gives sum 2.
\left(v^{2}-6v\right)+\left(8v-48\right)
Rewrite v^{2}+2v-48 as \left(v^{2}-6v\right)+\left(8v-48\right).
v\left(v-6\right)+8\left(v-6\right)
Factor out v in the first and 8 in the second group.
\left(v-6\right)\left(v+8\right)
Factor out common term v-6 by using distributive property.
v=6 v=-8
To find equation solutions, solve v-6=0 and v+8=0.
\left(v-8\right)\times 6=-v\left(-4+v\right)
Variable v cannot be equal to any of the values 0,4,8 since division by zero is not defined. Multiply both sides of the equation by v\left(v-8\right)\left(v-4\right), the least common multiple of v^{2}-4v,8-v.
6v-48=-v\left(-4+v\right)
Use the distributive property to multiply v-8 by 6.
6v-48=4v-v^{2}
Use the distributive property to multiply -v by -4+v.
6v-48-4v=-v^{2}
Subtract 4v from both sides.
2v-48=-v^{2}
Combine 6v and -4v to get 2v.
2v-48+v^{2}=0
Add v^{2} to both sides.
v^{2}+2v-48=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{-2±\sqrt{2^{2}-4\left(-48\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 2 for b, and -48 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
v=\frac{-2±\sqrt{4-4\left(-48\right)}}{2}
Square 2.
v=\frac{-2±\sqrt{4+192}}{2}
Multiply -4 times -48.
v=\frac{-2±\sqrt{196}}{2}
Add 4 to 192.
v=\frac{-2±14}{2}
Take the square root of 196.
v=\frac{12}{2}
Now solve the equation v=\frac{-2±14}{2} when ± is plus. Add -2 to 14.
v=6
Divide 12 by 2.
v=-\frac{16}{2}
Now solve the equation v=\frac{-2±14}{2} when ± is minus. Subtract 14 from -2.
v=-8
Divide -16 by 2.
v=6 v=-8
The equation is now solved.
\left(v-8\right)\times 6=-v\left(-4+v\right)
Variable v cannot be equal to any of the values 0,4,8 since division by zero is not defined. Multiply both sides of the equation by v\left(v-8\right)\left(v-4\right), the least common multiple of v^{2}-4v,8-v.
6v-48=-v\left(-4+v\right)
Use the distributive property to multiply v-8 by 6.
6v-48=4v-v^{2}
Use the distributive property to multiply -v by -4+v.
6v-48-4v=-v^{2}
Subtract 4v from both sides.
2v-48=-v^{2}
Combine 6v and -4v to get 2v.
2v-48+v^{2}=0
Add v^{2} to both sides.
2v+v^{2}=48
Add 48 to both sides. Anything plus zero gives itself.
v^{2}+2v=48
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.
v^{2}+2v+1^{2}=48+1^{2}
Divide 2, the coefficient of the x term, by 2 to get 1. Then add the square of 1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
v^{2}+2v+1=48+1
Square 1.
v^{2}+2v+1=49
Add 48 to 1.
\left(v+1\right)^{2}=49
Factor v^{2}+2v+1. 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+1\right)^{2}}=\sqrt{49}
Take the square root of both sides of the equation.
v+1=7 v+1=-7
Simplify.
v=6 v=-8
Subtract 1 from both sides of the equation.
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