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3\left(c+2\right)=-5c\left(c+2\right)
Variable c cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by c+2.
3c+6=-5c\left(c+2\right)
Use the distributive property to multiply 3 by c+2.
3c+6=-5c^{2}-10c
Use the distributive property to multiply -5c by c+2.
3c+6+5c^{2}=-10c
Add 5c^{2} to both sides.
3c+6+5c^{2}+10c=0
Add 10c to both sides.
13c+6+5c^{2}=0
Combine 3c and 10c to get 13c.
5c^{2}+13c+6=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=13 ab=5\times 6=30
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 5c^{2}+ac+bc+6. To find a and b, set up a system to be solved.
1,30 2,15 3,10 5,6
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 30.
1+30=31 2+15=17 3+10=13 5+6=11
Calculate the sum for each pair.
a=3 b=10
The solution is the pair that gives sum 13.
\left(5c^{2}+3c\right)+\left(10c+6\right)
Rewrite 5c^{2}+13c+6 as \left(5c^{2}+3c\right)+\left(10c+6\right).
c\left(5c+3\right)+2\left(5c+3\right)
Factor out c in the first and 2 in the second group.
\left(5c+3\right)\left(c+2\right)
Factor out common term 5c+3 by using distributive property.
c=-\frac{3}{5} c=-2
To find equation solutions, solve 5c+3=0 and c+2=0.
c=-\frac{3}{5}
Variable c cannot be equal to -2.
3\left(c+2\right)=-5c\left(c+2\right)
Variable c cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by c+2.
3c+6=-5c\left(c+2\right)
Use the distributive property to multiply 3 by c+2.
3c+6=-5c^{2}-10c
Use the distributive property to multiply -5c by c+2.
3c+6+5c^{2}=-10c
Add 5c^{2} to both sides.
3c+6+5c^{2}+10c=0
Add 10c to both sides.
13c+6+5c^{2}=0
Combine 3c and 10c to get 13c.
5c^{2}+13c+6=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.
c=\frac{-13±\sqrt{13^{2}-4\times 5\times 6}}{2\times 5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, 13 for b, and 6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
c=\frac{-13±\sqrt{169-4\times 5\times 6}}{2\times 5}
Square 13.
c=\frac{-13±\sqrt{169-20\times 6}}{2\times 5}
Multiply -4 times 5.
c=\frac{-13±\sqrt{169-120}}{2\times 5}
Multiply -20 times 6.
c=\frac{-13±\sqrt{49}}{2\times 5}
Add 169 to -120.
c=\frac{-13±7}{2\times 5}
Take the square root of 49.
c=\frac{-13±7}{10}
Multiply 2 times 5.
c=-\frac{6}{10}
Now solve the equation c=\frac{-13±7}{10} when ± is plus. Add -13 to 7.
c=-\frac{3}{5}
Reduce the fraction \frac{-6}{10} to lowest terms by extracting and canceling out 2.
c=-\frac{20}{10}
Now solve the equation c=\frac{-13±7}{10} when ± is minus. Subtract 7 from -13.
c=-2
Divide -20 by 10.
c=-\frac{3}{5} c=-2
The equation is now solved.
c=-\frac{3}{5}
Variable c cannot be equal to -2.
3\left(c+2\right)=-5c\left(c+2\right)
Variable c cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by c+2.
3c+6=-5c\left(c+2\right)
Use the distributive property to multiply 3 by c+2.
3c+6=-5c^{2}-10c
Use the distributive property to multiply -5c by c+2.
3c+6+5c^{2}=-10c
Add 5c^{2} to both sides.
3c+6+5c^{2}+10c=0
Add 10c to both sides.
13c+6+5c^{2}=0
Combine 3c and 10c to get 13c.
13c+5c^{2}=-6
Subtract 6 from both sides. Anything subtracted from zero gives its negation.
5c^{2}+13c=-6
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{5c^{2}+13c}{5}=-\frac{6}{5}
Divide both sides by 5.
c^{2}+\frac{13}{5}c=-\frac{6}{5}
Dividing by 5 undoes the multiplication by 5.
c^{2}+\frac{13}{5}c+\left(\frac{13}{10}\right)^{2}=-\frac{6}{5}+\left(\frac{13}{10}\right)^{2}
Divide \frac{13}{5}, the coefficient of the x term, by 2 to get \frac{13}{10}. Then add the square of \frac{13}{10} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
c^{2}+\frac{13}{5}c+\frac{169}{100}=-\frac{6}{5}+\frac{169}{100}
Square \frac{13}{10} by squaring both the numerator and the denominator of the fraction.
c^{2}+\frac{13}{5}c+\frac{169}{100}=\frac{49}{100}
Add -\frac{6}{5} to \frac{169}{100} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(c+\frac{13}{10}\right)^{2}=\frac{49}{100}
Factor c^{2}+\frac{13}{5}c+\frac{169}{100}. 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(c+\frac{13}{10}\right)^{2}}=\sqrt{\frac{49}{100}}
Take the square root of both sides of the equation.
c+\frac{13}{10}=\frac{7}{10} c+\frac{13}{10}=-\frac{7}{10}
Simplify.
c=-\frac{3}{5} c=-2
Subtract \frac{13}{10} from both sides of the equation.
c=-\frac{3}{5}
Variable c cannot be equal to -2.