Solve for p
p=2
p=-2
Share
Copied to clipboard
p^{2}-8p^{2}=-28
Multiply both sides of the equation by 2.
-7p^{2}=-28
Combine p^{2} and -8p^{2} to get -7p^{2}.
p^{2}=\frac{-28}{-7}
Divide both sides by -7.
p^{2}=4
Divide -28 by -7 to get 4.
p=2 p=-2
Take the square root of both sides of the equation.
p^{2}-8p^{2}=-28
Multiply both sides of the equation by 2.
-7p^{2}=-28
Combine p^{2} and -8p^{2} to get -7p^{2}.
-7p^{2}+28=0
Add 28 to both sides.
p=\frac{0±\sqrt{0^{2}-4\left(-7\right)\times 28}}{2\left(-7\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -7 for a, 0 for b, and 28 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
p=\frac{0±\sqrt{-4\left(-7\right)\times 28}}{2\left(-7\right)}
Square 0.
p=\frac{0±\sqrt{28\times 28}}{2\left(-7\right)}
Multiply -4 times -7.
p=\frac{0±\sqrt{784}}{2\left(-7\right)}
Multiply 28 times 28.
p=\frac{0±28}{2\left(-7\right)}
Take the square root of 784.
p=\frac{0±28}{-14}
Multiply 2 times -7.
p=-2
Now solve the equation p=\frac{0±28}{-14} when ± is plus. Divide 28 by -14.
p=2
Now solve the equation p=\frac{0±28}{-14} when ± is minus. Divide -28 by -14.
p=-2 p=2
The equation is now solved.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}