Use the quadratic formula to solve the quadratic equation.
-$5 p ^ { 2 } - 7 p = 7$
A) $\mathrm { p } = \frac { - 7 \pm 3 \sqrt { 21 } } { 10 }$
B) $\mathrm { p } = \frac { 7 \pm \sqrt { 119 } } { 20 }$
C) $\mathrm { p } = \frac { 7 \pm 3 \sqrt { 21 } } { 10 }$
D) $p = \frac { 7 \pm 3 \sqrt { 21 } } { 5 }$

Question

Quizplus · Accepted Answer

The quadratic formula is $ p = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} $. For the equation $5p^2 - 7p - 7 = 0$, $a = 5$, $b = -7$, and $c = -7$. Plugging these into the formula gives $ p = \frac{7 \pm \sqrt{(-7)^2 - 4 \cdot 5 \cdot (-7)}}{10} = \frac{7 \pm \sqrt{49 + 140}}{10} = \frac{7 \pm \sqrt{189}}{10} = \frac{7 \pm 3\sqrt{21}}{10} $.

Use the Quadratic Formula to Solve the Quadratic Equation 5p2−7p=75 p ^ { 2 } - 7 p = 75p2−7p=7

Use the Quadratic Formula to Solve the Quadratic Equation $5 p ^ { 2 } - 7 p = 7$