word problem!does anyone get this? how do i set it up

[really lost]

:?

chuck and dana agree to meet in chicago for the weekend. chick travel 143 miles in the same time dana travels 128 miles. if chucks rate of travel is 3mph more than danas, and they travel the same length of time, at what speed does chuck travel?

 

[tkhunny]

Come on...

Name Stuff.
Translate one phrase at a time.

Let's see what you get, one piece at a time.

 

[soroban]

Hello, really lost!

Chuck and Dana agree to meet in Chicago for the weekend.
Chuck travel 143 miles in the same time Dana travels 128 miles.
If Chuck's speed is 3mph more than Dana's, and they travel the same length of time,
at what speed does Chuck travel?

We will use the familiar: .Distance .= .Speed x Time
. . specifically, this variation: .Time .= .Distance ÷ Speed . **

Let D = Dana's speed (in mph).
Then D + 3 = Chuck's speed.

Chuck drove 143 miles at D+3 mph. .His time was: 143/(D+3) hours.

Dana drove 128 miles at D mph. .His time was: 128/D hours.

. . . . . . . . . . . . . . . . . . . .143 . . . . . 128
Their times are equal: . -------- . = . ----- . . . . . There!
. . . . . . . . . . . . . . . . . . . D + 3 . . . . . D

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

** How do we know which variation to use?

Read the problem again . . .
. . They have different distances and different speeds.
. . But their <u>times</u> are the same.
And <u>that</u> is what we will equate . . . see?

 

[really lost]

well ive gotten that far already but then its like to i get a common denominator and then i have an x on both sides and i never come out with a number....................ahhhh im sooo not gunna passs

 

[really lost]

sooo are you not supposed to end up with a number????


or is it because its multiple choice you have to plug all the given numbers in and see what works????

 

[Denis]

if a/x = b/y, then ay = bx : known as crisscross multiplication

your equation is similar: 128 / x = 143 / (x+3)
128(x+3) = 143x
128x + 384 = 143x
I take it you can finish it?