Problema Solution
Felipe is driving to Dallas. Suppose that the distance to his destination (in miles) is a linear function of his total driving time (in minutes). Felipe has
57
miles to his destination after
21
minutes of driving, and he has
45
miles to his destination after
37
minutes of driving. How many miles will he have to his destination after
49
minutes of driving
Answer provided by our tutors
A linear function has the following form:
y = a + bx
In our case y will be the destination and x the time.
y = 57 mi for x = 21 min
a + 21b = 57
y = 45 mi for x = 37 min
a + 37b = 45
We have the following system of equations:
a + 21b = 57
a + 37b = 45
........
click here to see the system of equations solved for a and b
........
a = 291/4
b = - 3/4
y = 291/4 + (-3/4)x
Plug x = 49 min
y = 291/4 + (-3/4)*49
y = 36 mi
Felipe has 36 miles to his destination after 49 minutes of driving.