Answer:
The speed of the Zach travelling is 8 miles per hour.
The speed of the Warren travelling is 15 miles per hour.
Step-by-step explanation:
Given : Zach and Warren both leave the coffee shop at the same time, but in opposite directions. If Warren travels 7 mph faster than Zach and after 7 hours they are 161 miles apart.
To find : How fast is each traveling?
Solution :
Let the speed of Zach is x mile per hour.
If Warren travels 7 mph faster than Zach
The speed of the Warren is x+7 miles per hour.
Zach and Warren both leave the coffee shop at the same time, but in opposite directions.
The distance covered is 161 miles in 7 hours.
We know, 
Substitute,






The speed of Warren is 8+7=15
The speed of the Zach travelling is 8 miles per hour.
The speed of the Warren travelling is 15 miles per hour.