If Cheryl paid $8.10 using a ten dollar bill, then her change would be $1.90.
Total distance John drove=450 miles
total time=8 hours
let the number of hours he drove on highway be x, number of hours he drove on turnpike will be (8-x) hours
since
distance=speed*time
distance traveled in highway=50x
distance traveled in turnpike=60(8-x)
thus the total distance will be:
50x+60(8-x)=450
simplifying the above
50x+480-60x=450
-10x=450-480
-10x=-30
thus
x=3 hours
Thus he drove on highway for 3 hours.
Consider the coordinate plane:
1. The origin is the point where Sharon and Jacob started - (0,0).
2. North - positive y-direction, south - negetive y-direction.
3. East - positive x-direction, west - negative x-direction.
Then,
- if Jacob walked 3 m north and then 4 m west, the point where he is now has coordinates (-4,3);
- if Sharon walked 5 m south and 12 m east, the point where she is now has coordinates (12,-5).
The distance between two points with coordinates
and
can be calculated using formula

Therefore, the distance between Jacob and Sharon is
