A 150-pound person uses 5.1 calories per minute when walking at a speed of 4 mph. how long must a person walk at this speed to use at least 180 calories?
a person must walk for at least
in order to use at least 180 calories.
(round up to the nearest minute.)

Let 't' represent the time of the walk in minutes.

5.1*t = 220

t = 43.14 min

The person needs to walk at least 43.14 minutes to but at least 220 calories.

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!

i think it will be zero as slope has a formula of difference between initial and final distance divided by itz time interval