Answer:
46 mph and 61 mph
Step-by-step explanation:
Distance=speed*time
Let speed of one bus be x and another x+15
After 3 hours
First bus would have traveled 3x while second bus 3(x+15)=3x+45
Total distance= 3x+3x+45=6x+45
6x+45=321
6x=321-45=276
x=276/6=46 mph
x+15=46+15=61 mph
<span>-----
x/8 = 18/x
---
x^2 = 8*18</span>
5
you use the formula a^2+b^2=c^2
a=3, b=4
3*3=9 and 4*4=16
16+9=25
square root of 25 is 5.
5 is the answer