Distance = 30 mph * time
distance = 4 mph * time
distance = 30 mph * t
distance = 4 mph * (17-t)
Since distance is equal then
30 mph * t = 4 mph * (17-t)
30t = -4t + 68
34t = 68
t = 2 hours
We see the return trip time is (17 -t ) which is 15 hours.
The beginning trip time is 2 hours.
Double Check
Beginning trip = 30 miles * 2 = 60 miles
Return trip = 4 miles * 15 = 60 miles.
Answer:
Third graph in the photo
Step-by-step explanation:
x^2+3x-4 can be factored as (x+4)(x-1). When y=0, x must be -4 or 1 to satisfy the equations, and thus the roots of the graph are at x=-4 and x=1. When x=0, y=(4)(-1)=-4. The only graph that satisfies both of these requirements is the third/last one.
The answer is 3.9 x 10^-5
