I think the answer is 5×500
<span>-8(n+3)+28=-5n-5
-8n-24+28=-5n-5
</span>-8n+4=-5n-5
-8n+4-4=-5n-5-4
-8n=-5n-9
-8n+5n=-5n+5n-9
-3n=-9
-3n/-3=-9/-3
n=3
n=3 is the correct answer
1km = 1000m
1hr = 3600sec
Do proportions:
1km / 1000m = 15km / x
15000m = x
1hr = 3600sec
15000/3600 = 4.2m per second
Choice 4
648.566 Km is the answer. :)