Two buses leave a station at the time and travel in opposite directions. One bus travel 18 mi/h slower then the other l. If the two buses are 670mi apart after 5 hours what is the rate of each bus

Well let's call the fast bus b

That means the slow bus will be b-18

We know they travel in 5 hours, so multiply them both by 5

So 5b + 5b - 90 = 670

Simplify it down and collect like terms

10b = 580

Isolate b by dividing both by 10

b = 58

The fast bus travelled at 58mph

We know the slow bus travels 18mph slower than the fast one

58 - 18 = 40

The slow bus travels at 40mph