Quadratic Equation prob: x - 10 - 20 square root (x - 2) +  TOPIC_SOLVED

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.

Quadratic Equation prob: x - 10 - 20 square root (x - 2) +

Postby DrO on Sat May 16, 2009 2:24 am

How do you attempt a problem like this?

x - 10 - 20 square root (x - 2) + 30 = 0

Sorry I recently joined and don't know how to put the square root sign in. There is a square root sign above the (x - 2). If someone can tell me how to put in the square root sign I will repost the question.
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Re: Quadratic Equation problem

Postby Martingale on Sat May 16, 2009 4:09 am

DrO wrote:How do you attempt a problem like this?

x - 10 - 20 square root (x - 2) + 30 = 0

Sorry I recently joined and don't know how to put the square root sign in. There is a square root sign above the (x - 2). If someone can tell me how to put in the square root sign I will repost the question.





Code: Select all
[tex]x-10-20\sqrt{x-2}+30=0[/tex]
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Re: Quadratic Equation problem

Postby Martingale on Sat May 16, 2009 4:17 am

DrO wrote:How do you attempt a problem like this?

x - 10 - 20 square root (x - 2) + 30 = 0

Sorry I recently joined and don't know how to put the square root sign in. There is a square root sign above the (x - 2). If someone can tell me how to put in the square root sign I will repost the question.



try letting
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  TOPIC_SOLVED

Postby stapel_eliz on Sat May 16, 2009 1:52 pm

DrO wrote:How do you attempt a problem like this?

x - 10 - 20 square root (x - 2) + 30 = 0

A good first step for solving radical equations is to try to isolate the radical:

. . . . .

. . . . .

. . . . .

Then square both sides:

. . . . .

Keep in mind that (x + 20)2 means (x + 20)(x + 20), and multiply out the square:

. . . . .

. . . . .

Then gather everything together onto one side:

. . . . .

Simplify, and then solve the quadratic by whatever method you prefer.

If you get stuck, please reply showing your work and reasoning so far. Thank you! :D
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Re: Quadratic Equation problem

Postby Martingale on Sat May 16, 2009 5:48 pm

Martingale wrote:
DrO wrote:How do you attempt a problem like this?

x - 10 - 20 square root (x - 2) + 30 = 0

Sorry I recently joined and don't know how to put the square root sign in. There is a square root sign above the (x - 2). If someone can tell me how to put in the square root sign I will repost the question.



try letting


using the substitution above you can also solve the equation




substituting back into your equation you get...



simplify and solve for u ... and then for x
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