Answer:
x = (571 ± √186217) / 18
x ≈ 7.74840677368558702303.. or 55.69603767075885742140..
x ≈ 7.75 or 55.70
Explanation:
y = -9x² + 571x – 3884.
x = (-b ± √b² – 4ac) / 2a
x =
(-(571) ± √((571)² – 4((-9) × (-3884))) / 2(-9)) →
(-571 ± √(326041 – 4(34956))) / -18) →
(-571 ± √(326041 – 139824)) / -18) →
(-571 ± √(186217)) / -18 →
(571 ± √186217) / 18 →