rational expressions/ word problems

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jburgswife30

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If one-half of one interger is subtracted from three-fifths of the next consecutive interger, the difference is 3. What are the two intergers?

I am not even sure how to start, I am horrible at word problems. Here is one more.

Kevin earned $165 interest for 1 year on an investment of $1500. At the same rate, what amount of interest would be earned by an investment of $2500?
 
jburgswife30 said:
If one-half of one interger is subtracted from three-fifths of the next consecutive interger, the difference is 3. What are the two intergers?

I am not even sure how to start, I am horrible at word problems. Here is one more.

Kevin earned $165 interest for 1 year on an investment of $1500. At the same rate, what amount of interest would be earned by an investment of $2500?
Click to expand...

I'll start you off:

(To quote tkhunny) Name stuff:

First integer = f

next consequitive integer = f + 1

then

"If one-half of one interger" = f/2

"three-fifths of the next consecutive interger" = 3/5 * (f+1)

Then the problem states

If one-half of one interger is subtracted from three-fifths of the next consecutive interger, the difference is 3

How would wou write that mathe matically?

3/5 * (f+1) - f/2 = 3

Now solve for 'f' from above....

#2

Same process:

Name stuff ......

Now show your work indicating exactly where you are stuck - so that we can help you better.
 
jburgswife30 said:
If one-half of one interger is subtracted from three-fifths of the next consecutive interger, the difference is 3. What are the two intergers?
Click to expand...
If x/2 is subtracted from (3/5))(x + 1) = 3 then,
3(x + 1)/5 - x/2 = 3

I imagine you can take it from here.

jburgswife30 said:
Kevin earned $165 interest for 1 year on an investment of $1500. At the same rate, what amount of interest would be earned by an investment of $2500?
Click to expand...
If $1500 earns $165 in interest, $2500 will earn
165(2500/1500) dollars.
 
ok, is this right?

Ariana took 2 hr longer to drive 360mi on the first day of a trip than she took to drive 270mi on the second day. If her speed was the same on both days, what was the driving time each day.

270/t=360/t+2

t(t+2)(270/t)=t(t+2)(360/t+2)
270(t+2)+360t
270t+540=360t
540=90t
t=6hr

270mi trip= 6hr
360mi trip=8hr

If this is right how do I check it?
 
There are two conditions to be met:

(1) 2 hr longer --------- answers meets this condition

(2)her speed was the same on both days

speed the second day = 270/6 = 45 mph

speed the first day = 300/8 = 45 mph

Checks.... your answers are most probably correct
 
Subhotosh made his first typo this year: should be 360 ; 360/8 = 45, right?
 
thanks guys, I am still working on 3 more but then I am done, WHEW I can't wait till this class is over
 
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