word problem chaos: Suppose that you drive 28 miles to an Easter dinner & it takes...

[atlmixcoatl]

word problem chaos: Suppose that you drive 28 miles to an Easter dinner & it takes...

Suppose that you drive 28 miles to an Easter dinner and it takes you 1.26 hours to get there. Suppose that your speed during the second 14 miles was 5MPH faster than your speed during the first 14 miles. what was your speed during the first 14 miles?

my formula was 14x + 14 (x+50) =1.26
then it becomes 28x =70 = 125x2 +6.25
and then i'm stuck.

 

[mmm4444bot]

Suppose that you drive 28 miles to an Easter dinner and it takes you 1.26 hours to get there. Suppose that your speed during the second 14 miles was 5MPH faster than your speed during the first 14 miles. what was your speed during the first 14 miles?

my formula was 14x + 14 (x+50) =1.26
then it becomes 28x =70 = 125x^2 +6.25
and then i'm stuck.

We show exponents using the caret symbol: ^

Also, it's good form to always define your variable(s), like this:

Let x = the speed during the first 14 miles

In your first equation, you wrote x+50; did you intend to type x+5, instead? (You wrote that the second speed is 5mph faster, not 50mph faster.)

Your first equation is:

14x + 14(x + 50) = 1.26

This is not correct because 14 is a distance and x is a rate, but Distance*Rate does not equal Time.

Time = Distance/Rate

Also, your second equation does not follow from the first.

28x = 70 = 125x^2 + 6.25

Plus, why are there two equals signs?

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You need to start over.

Using D, R, and T for Distance, Rate (i.e., speed), and Time, we have the following relationships.

D = R*T ("Distance equals Rate times Time")

Dividing both sides by R, we get:

T = D/R ("Time equals Distance divided by Rate")

Now, this exercise involves two Rates and two Times.

For the first half of the trip:

Rate = x
Time = t

For the second half of the trip:

Rate = x+5
Time = 1.26-t

We can also express t in terms of x because (from the first half of the trip) we have:

14 = x*t. Divide both sides by x.

t = 14/x

Using all of this information, try to write your equation again. Show us what you get.

And, please use the [Preview Post] button to proofread your typing, before you submit your posts. :cool: