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

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
DrO
Posts: 1
Joined: Sat May 16, 2009 2:16 am
Contact:

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

Postby DrO » 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.

User avatar
Martingale
Posts: 350
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA
Contact:

Re: Quadratic Equation problem

Postby Martingale » 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]

User avatar
Martingale
Posts: 350
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA
Contact:

Re: Quadratic Equation problem

Postby Martingale » 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

User avatar
stapel_eliz
Posts: 1733
Joined: Mon Dec 08, 2008 4:22 pm
Contact:

Postby stapel_eliz » 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

User avatar
Martingale
Posts: 350
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA
Contact:

Re: Quadratic Equation problem

Postby Martingale » 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


Return to “Intermediate Algebra”