Solve for p
p=-3
p=-\frac{1}{6}\approx -0.166666667
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19p+6p^{2}+3=0
Add 3 to both sides.
6p^{2}+19p+3=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=19 ab=6\times 3=18
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 6p^{2}+ap+bp+3. To find a and b, set up a system to be solved.
1,18 2,9 3,6
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 18.
1+18=19 2+9=11 3+6=9
Calculate the sum for each pair.
a=1 b=18
The solution is the pair that gives sum 19.
\left(6p^{2}+p\right)+\left(18p+3\right)
Rewrite 6p^{2}+19p+3 as \left(6p^{2}+p\right)+\left(18p+3\right).
p\left(6p+1\right)+3\left(6p+1\right)
Factor out p in the first and 3 in the second group.
\left(6p+1\right)\left(p+3\right)
Factor out common term 6p+1 by using distributive property.
p=-\frac{1}{6} p=-3
To find equation solutions, solve 6p+1=0 and p+3=0.
6p^{2}+19p=-3
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.
6p^{2}+19p-\left(-3\right)=-3-\left(-3\right)
Add 3 to both sides of the equation.
6p^{2}+19p-\left(-3\right)=0
Subtracting -3 from itself leaves 0.
6p^{2}+19p+3=0
Subtract -3 from 0.
p=\frac{-19±\sqrt{19^{2}-4\times 6\times 3}}{2\times 6}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 6 for a, 19 for b, and 3 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
p=\frac{-19±\sqrt{361-4\times 6\times 3}}{2\times 6}
Square 19.
p=\frac{-19±\sqrt{361-24\times 3}}{2\times 6}
Multiply -4 times 6.
p=\frac{-19±\sqrt{361-72}}{2\times 6}
Multiply -24 times 3.
p=\frac{-19±\sqrt{289}}{2\times 6}
Add 361 to -72.
p=\frac{-19±17}{2\times 6}
Take the square root of 289.
p=\frac{-19±17}{12}
Multiply 2 times 6.
p=-\frac{2}{12}
Now solve the equation p=\frac{-19±17}{12} when ± is plus. Add -19 to 17.
p=-\frac{1}{6}
Reduce the fraction \frac{-2}{12} to lowest terms by extracting and canceling out 2.
p=-\frac{36}{12}
Now solve the equation p=\frac{-19±17}{12} when ± is minus. Subtract 17 from -19.
p=-3
Divide -36 by 12.
p=-\frac{1}{6} p=-3
The equation is now solved.
6p^{2}+19p=-3
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{6p^{2}+19p}{6}=-\frac{3}{6}
Divide both sides by 6.
p^{2}+\frac{19}{6}p=-\frac{3}{6}
Dividing by 6 undoes the multiplication by 6.
p^{2}+\frac{19}{6}p=-\frac{1}{2}
Reduce the fraction \frac{-3}{6} to lowest terms by extracting and canceling out 3.
p^{2}+\frac{19}{6}p+\left(\frac{19}{12}\right)^{2}=-\frac{1}{2}+\left(\frac{19}{12}\right)^{2}
Divide \frac{19}{6}, the coefficient of the x term, by 2 to get \frac{19}{12}. Then add the square of \frac{19}{12} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
p^{2}+\frac{19}{6}p+\frac{361}{144}=-\frac{1}{2}+\frac{361}{144}
Square \frac{19}{12} by squaring both the numerator and the denominator of the fraction.
p^{2}+\frac{19}{6}p+\frac{361}{144}=\frac{289}{144}
Add -\frac{1}{2} to \frac{361}{144} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(p+\frac{19}{12}\right)^{2}=\frac{289}{144}
Factor p^{2}+\frac{19}{6}p+\frac{361}{144}. 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(p+\frac{19}{12}\right)^{2}}=\sqrt{\frac{289}{144}}
Take the square root of both sides of the equation.
p+\frac{19}{12}=\frac{17}{12} p+\frac{19}{12}=-\frac{17}{12}
Simplify.
p=-\frac{1}{6} p=-3
Subtract \frac{19}{12} from both sides of the equation.
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