Answer:
Mile marker 114
Step-by-step explanation:
Our slope is 60 mph
Let x be the time in hours and y be the miles
Our point is (1 ,84)
We have a point and a slope
We can use point slope form to find the equation
y-y1 = m(x-x1)
y-84 = 60(x-1)
We want to find y when the time is 90 minutes
We need to change 90 to hours
90 minutes * 1 hour/60 minutes = 1.5 hours
Substitute this into the equation to find the miles, which is the mile marker
y - 84 = 60 (1.5 -1)
y - 84 = 60(.5)
y -84 = 30
Add 84 to each side
y-84+84 = 30+84
y = 114
You should pass mile marker 114
