Answer:
1.95secs
Step-by-step explanation:
Given the height of the float expressed as h(t) = -16t2 - 3t + 55.
The floats reach the swimmer at h(t) = 0
Substitute
0 = -16t^2 - 3t + 55.
16t^2 + 3t - 55 = 0
Using the general formula;
t = -3±√3²-4(16)(-55)/2(16)
t = 3±√9+3520/32
t = 3±√3529/32
t = 3+59.41/32
t = 62.41/32
t = 1.95
Hence it will take 1.95secs
Answer:

Step-by-step explanation:
Answer: The charge was right.
Step-by-step explanation:
If he charged $18 per hour, it means he charged $18 for 60 minutes. He worked for 2 hours 15 minutes which is (60 ×2) + 15 = 135 minutes. For 135 mins, (135 ×18)÷ 60 = 40.5.
He drove 21 miles to his house and 21 miles back. That is 21×2= 42. And for $0.27 = $11.34.
Adding the costs, 40.5 + 11.34 = $51.84