B={x|x is an even whole no less than 9}
Now

When the firecracker hits the ground, H(t) = 0.0 = -16t^2 + 90t + 160 Using the quadratic formula,t = (-90 +- sqrt(90^2 - 4(-16)(160))) / 2(-16)t = -1.42 ort = 7.04
The negative time is extraneous. Therefore,t = 7.04 s.
Seven Seconds is your answer!
Answer:
A) d = 48t, d in miles, t in hours
B)d = 32t, d in miles, t in hours
C)y = 8 mph
Step-by-step explanation:
16 miles in 20 mins = 48 mph
16 miles in 30 mins = 32 mph
The boat speed is the average = (48 + 32)/2 = 40 mph
The current is the difference = 8 mph
Add together the time it takes to put on the four wheels and the hood.
2.054s +3.652s = 5.704s
multiple this answer by 42
5.706s times 42= 239.652s
answer number two is correct