Question

Which of the following is a solution to the quadratic equation −x2+x=−10
? Assume that the solution has been rounded to the nearest hundredth, if applicable.(1 point)

x = 0.77

x = 0.27

x = 1.7

x = 3.7

Answer 1

Solve x^2 − x − 10 = 0 (multiply original by −1).
x = [1 ± sqrt(1 + 40)]/2 = [1 ± sqrt(41)]/2.
sqrt(41) ≈ 6.4031 so the positive root ≈ (1 + 6.4031)/2 = 3.7016 ≈ 3.70.

Answer: x = 3.7.