Answer:
Step-by-step explanation:
30t - 5t² = 10
5t² - 30t + 10 = 0
t = [30 ± √(30² - 4 ⋅ 5 ⋅ 10)] / [2 ⋅ 5]
= [30 ± √700] / 10
= [30 ± 10√7] / 10
= 3 ± √7
≈ 0.35 seconds and 5.65 seconds
