Question

Use the quadratic formula to solve x^2 + 7x + 8 = 0. Estimate irrational solutions to the nearest tenth.


A.
{–12, 5}

B.
{–11.1, –2.9}

C.
{–5.6, –1.4}

D.
{–3.9, 12.1}

Answer 1

\(\large \bf ax^2+bx+c\\\quad\\

\text{quadratic formula}\\
x= \cfrac{ - b \pm \sqrt { b^2 -4ac}}{2a}\)

Answer 2

In other words.....

Answer 3

\(\bf x^2 + 7x + 8 = 0\\ \quad \\

x= \cfrac{ - b \pm \sqrt { b^2 -4ac}}{2a}\implies x= \cfrac{ - (7) \pm \sqrt { (7)^2 -4(1)(8)}}{2(1)}\)

Answer 4

Actual: x=−1.4384471871911697 and x=−5.561552812808831