Question

Joline is solving the equation 0 = x2 – 5x – 4 using the quadratic formula. Which value is the negative real number solution to her quadratic equation? Round to the nearest tenth if necessary.

Quadratic formula: x = StartFraction negative b plus or minus StartRoot b squared minus 4 a c EndRoot Over 2 a EndFraction

–5.7
–4
–1
–0.7

Answer 1

-0.7

Explanation:

x² - 5x - 4 = 0

x = {-(-5) ± √[(-5)² - 4(1)(-4)]}/(2 × 1)

x = {5 ± √[25 + 16]}/2

x = (5 + √41)/2 or x = (5 - √41)/2

x ≈ 5.702 or x = -0.702

Answer: -0.7