Solve by using the quadratic formula
-$\mathrm{x}^{2}-\mathrm{x}-56=0$
A) $\{7,8\}$
B) $\{-8,7\}$
C) $\{-7,-8\}$
D) $\{-7,8\}$

Question

Quizplus · Accepted Answer

The quadratic formula is $x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}$ for a quadratic equation $ax^2 + bx + c = 0$. Here, $a=1$, $b=-1$, and $c=-56$. Plugging these into the formula gives $x = \frac{1 \pm \sqrt{1+4*56}}{2} = \frac{1 \pm \sqrt{225}}{2} = \frac{1 \pm 15}{2}$, which results in $x = 8$ and $x = -7$.

Solve by Using the Quadratic Formula - x2−x−56=0\mathrm{x}^{2}-\mathrm{x}-56=0x2−x−56=0 A) {7,8}\{7,8\}{7,8} B) {−8,7}\{-8,7\}{−8,7} C) {−7,−8}\{-7,-8\}{−7,−8}

Solve by Using the Quadratic Formula
- $\mathrm{x}^{2}-\mathrm{x}-56=0$ A) $\{7,8\}$ B) $\{-8,7\}$ C) $\{-7,-8\}$