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#26 Help Me ! » Word Problem » 2010-04-25 04:34:07

Spanky
Replies: 28

Examining the blueprints for a rectangular room that is 17 feet longer than it is wide, an electrician determines that a wire run diagonally across this room will be 54 feet long.  What is the width of this room?

#27 Re: Help Me ! » Quadratic Formual » 2010-04-09 15:23:34

Spanky

Thanks!

#28 Re: Help Me ! » Quadratic Formual » 2010-04-09 14:29:59

Spanky

Oh, Ok I see now.  Can you explain to me how you turned 75 + 25 square root 3191 / 6 into 25(3 + square root 3191) / 6?  I'm not seeing it...

#29 Re: Help Me ! » Quadratic Formual » 2010-04-09 13:56:34

Spanky

Hi Spanky;

Ok, maybe i should give you the full problem because the answer is supposed to be 247.87

Apply the Pythagorean theorem: Two planes depart simultaneously from an airport.  One flies due North, the other due west at a rate of 25 mi/h slower than the first plane. After 3 hours, radar indicates that the planes are 1000 mi apart.  What is the ground speed of each plane?  Let r be the ground speed of the first plane.

So I did:
Let r= the ground speed of first plane
r - 25 = the speed of second plane

a^2 + b^2 = c^2

(3r)^2 + [ 3(r-25)]^2 = (1000)^2

9r^2 + (3r-75)^2 = 1000000

9r^2 + (9r^2 - 450r + 5625) = 1000000

18r^2- 450r -994375= 0

Then I was going to use the Quadratic Formula to solve for the answer, which should turn out to be 247.87 mi/h.  Where did I make my mistake?

#30 Re: Help Me ! » Quadratic Formual » 2010-04-09 11:38:19

Spanky

Thanks bobby, but that's as far as i got.  I cant seem to get the answer.  I'm coming up with

x= 450 +- square root of 71797500 / 36

(Sorry, I dont know how to use the square root symbol on here)

#31 Re: Help Me ! » Square Root of a Negative Number » 2010-04-09 11:24:55

Spanky

smile Thanks!!

#32 Re: Help Me ! » Square Root of a Negative Number » 2010-04-09 11:17:30

Spanky

I got 2i square root 23

#33 Help Me ! » Quadratic Formual » 2010-04-09 11:15:59

Spanky
Replies: 9

Use the Quadratic Formula to solve:

18r^2 -450r -994375=0

#34 Re: Help Me ! » Square Root of a Negative Number » 2010-04-09 11:14:27

Spanky

Thanks Bobby, I understand it now.

#35 Help Me ! » Square Root of a Negative Number » 2010-04-08 07:29:47

Spanky
Replies: 6

how do you find the square root of -92?

#36 Re: Help Me ! » How to Factor... » 2010-03-28 13:50:53

Spanky

Yeah, I was hoping to simplify the problem and cross out things in the numerator and denominator.  It just seemed too big for an answer.  Thanks for checking my work!

#37 Re: Help Me ! » Inverse Variation Problem » 2010-03-28 11:40:34

Spanky

smile I get it now! Thanks!

#38 Re: Help Me ! » Direct Variation Word Problem » 2010-03-28 11:39:04

Spanky

Thank you, That was very helpful.  I understand it now.

#39 Help Me ! » How to Factor... » 2010-03-27 04:46:43

Spanky
Replies: 3

How do you factor:

x^3- 74x^2- 52x- 24

#40 Help Me ! » Direct Variation Word Problem » 2010-03-27 04:05:02

Spanky
Replies: 2

The number of pesos varies directly as the number of dollars exchanged. In 2000, one could exchange 30 dollars for 249.78 pesos.  What was the constant of variation (exchange rate) at that time?

#41 Help Me ! » Inverse Variation Problem » 2010-03-27 03:59:18

Spanky
Replies: 3

y varies inversely as x with a constant of variation of -20. Determine x when y is 26.

#42 Re: Help Me ! » Word Problem Help! » 2010-03-26 04:22:02

Spanky

I did.  I understand now that its like a substitution method problem.  It worked out well, I got the same answers and was able to do other problems like it.  Thanks again for your help!

#43 Re: Help Me ! » Inverse Variation » 2010-03-26 04:16:26

Spanky

Thank you! I get it now.

#44 Re: Help Me ! » Solve for X » 2010-03-26 04:12:25

Spanky

It doesnt equal anything.  the question is:

Solve \frac{X+4}{X-5}-y for X

Maybe set it equal to zero?

#45 Re: Help Me ! » Solve for X » 2010-03-25 11:16:09

Spanky

its X+4 divided by X-5 then minus y.  I couldnt figure out how else to write it.  Does it make sense now?

#46 Help Me ! » Inverse Variation » 2010-03-25 08:23:11

Spanky
Replies: 2

Z varies jointly as X and Y, and Z is 12 when X is 6 and Y is 4.  Find Z when X is 8 and Y is 10.

#47 Help Me ! » Solve for X » 2010-03-25 07:34:12

Spanky
Replies: 5

Solve  X +4/ X-5      -y    for X

#48 Re: Help Me ! » Word Problem Help! » 2010-03-24 16:19:09

Spanky

smile Thank you!!!

#49 Help Me ! » Word Problem Help! » 2010-03-24 16:04:15

Spanky
Replies: 4

A store mixes red seeds worth $10 per pound and blue seeds worth $13 per pound. The mixture is to sell for $11 per pound. Find how much of each should be used to make a 288 pound mixture.

How many red seeds should be in the mixture?
How many blue seeds should be in the mixture?

#50 Help Me ! » Writting an Equation » 2010-03-11 18:36:55

Spanky
Replies: 3

Write an equation for:

Quadratic with only one zero at the vertex point (-9,0) that is everywhere negative.

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