B= Exactly one solution
-6y+9y= 3y
3y+13=8y-3
3y=8y-16
-5y=-16
In order to find the area, you multiply the width (7), height (6) and length (12). But the problem states that the height has changed from 6 to 6 minus3, which would be 3. So you multiply 3, 7, and 12.
The answer to your question is x=-2y+4
55 miles is 290400 feet so you are driving at 290400 feet per hour now there are 60 minutes In an hours so divide
290400/60=4840
4840 feet per minute
there are 60 seconds in a minute so divide again
4840/60=80.67
80.67feet per second rounded