Answer:
10 hours
Step-by-step explanation:
We already have the equation, which is y = 30x + 20. Simply substitute 320 for y, and solve for x.
320 = 30x + 20
First, subtract 20 from both sides.
320 - 20 = 30x
300 = 30x
Now divide both sides by 30.
300/30 = x
10 = x
It will take about 10 hours for Robin to travel 320 miles.
