PLEASE HELP ME. :( :(

1. After 4 hours of driving, Jan is 248 miles away from home. After 6 hours of driving, she is 372 miles from home. Write an equation in point-slope form to
determine her distance y from home after x hours.

2. A train traveled 150 miles in 1 1/4 hours. At this rate, how far will the train travel after 5 hours?


Sagot :

y = mx + b

4 = m(248) + b
6 = m(372) + b
subtract the two equations to get
-2 = m(-124) + 0
m = 1/62

Then plug in m into one of the equations to find b
4 = (1/62)(248) + b
4 = 4 + b
b = 0

So the equation is
y = (1/62)x + 0
or
y = (1/62)x
or
y = x/62

edit: I totally didn't use point slope. It should be
        y + 0 = (1/62)(x + 0)
        or  y = (1/62)x

(since b is 0, that means she started driving directly at home)
-------------------
2) 150mi/1.25hr = Xmi/5hr
    750mi/1.25 = X
    X = 600miles
1. the slope formula is rise over run or y2-y1 over/divded by x2-x1 which in your case would be 372-248 over 6-4 so you would write m=y2-y1 over x2-x1 or m=372-248 over 6-4 (please be careful the numbers are small and goes at the bottom of the letter)

2.it would be 600 miles in 5 hours