Question

One car travels 270 miles in the same amount of time it takes a second car traveling 6 miles per hour slower than the first to go 234 miles. What are the speeds of the cars?

Answer 1

Car one speed is x, and car 2 speed is x-6
Both cars travel same amount of time. d= v x t so t= d/v
set the two times equal and solve for x

Explanation:

`270/x = 234/(x-6)`

`270(x-6) = 234x`

`270x-1620 = 234x`

`36x-1620= 0`

`36 x = 1620`

`x= 45mph`

Answer 2

`45" mph and "39" mph"`

Explanation:

`"using the formula"`

`• " average speed (S)"="distance (D)"/"time (T)"`

`T" is a constant quantity here"`

`color(blue)"car 1"`

`S=270/TrArrST=270to(1)`

`color(blue)"car 2"`

`S-6=234/TrArrST-6T=234to(2)`

`"subtract "(2)-(1)`

`rArr6T=270-234=36`

`rArrT=36/6=6" hours"`

`rArrcolor(blue)"car 1"toS=270/6=45" mph"`

`rArrcolor(blue)"car 2 "toS=234/6=39" mph"`