Question

jacob travels for 5 hours at a constant speed.The return trip takes 4 hours, traveling 15 mph faster,also at a constant speed.What was the distance each way and what were his speeds for each way?

Answer 1

use this formula d=rt

Answer 2

so 5x+4x+15=d

Answer 3

v2=v1+15
5v1=4(v1+15)
300 miles
60 MPH
75 MPH

Answer 4

please elaborate nsutton can i use x instead of v

Answer 5

I like to use v for velocity and x as a displacement, but that is only personal preference. the method is the same.

Answer 6

please break it down more

Answer 7

v2 is return velocity, v1 is first velocity.
solve for v1. solve for v2 using the value of v1. v1*5 gives the distance.

Answer 8

so if v1 is first velosity why wouldnt it be v1-15

Answer 9

v2 is v1+15mph

Answer 10

speed=distance/time.
let v1 be his first velocity.
x be the distance travelled in the two cases.
t be the time taken.

v1=x/5 in first case.
x=5*v........................(1)
in second case v2=v1+15.
v1+15=x/4
x=(v1+15)*4...............(2).
equate 1 and 2.
on simplification u get v1=15km/hr.
v2=15+15=30km/hr.
substitute v1 value in(1).
u get x=75km.

Answer 11

in (1) x=v1*5.

Answer 12

Re-simplify your equation @anusha.p

Answer 13

you did not distribute the four to the fifteen before grouping like terms.

Answer 14

yup.v1=60.
v2=75.
x=300.
i'm srry guys.

Answer 15

it's all good.

Answer 16

ty nsutton and anusha.p

Answer 17

and it is not km/hr.infact miles/hr.