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Problems To Quadratic Equations, HELP

shortys94 · 2005-09-27 15:54:01

Hello Have done every single sum given regarding these, but this one for some reason is giving me problems:( please work out this problem and post to show the workings, i basically want to know the equation One Whole Number is 3 larger than twice another whole number. The sum of the squares of these two numbers is 194.…

27-09-2005 3:54pm

#1

shortys94

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Hello
Have done every single sum given regarding these, but this one for some reason is giving me problems:(

please work out this problem and post to show the workings, i basically want to know the equation

One Whole Number is 3 larger than twice another whole number. The sum of the squares of these two numbers is 194. Find the two numbers.

THANKS, the thing i dont get really is the sum of the squares

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#2 27-09-2005 4:21pm

Pherekydes

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Let x,y be the two numbers.

y = 2*x + 5;

x^2 + y^2 = 194;

Sub for y in (2):

x^2 + (2*x + 3)^2 = 194;

x^2 + 4*x^2 + 12*x + 9 = 194;

5*x^2 + 12*x - 185 = 0;

The solns are x =(5, -37/5)

We want a whole number soln, so x = 5 is the one we want.

Thus y = 13.

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#3 27-09-2005 7:13pm

shortys94

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aorry but whats ^

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#4 27-09-2005 8:11pm

eoinf

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x^2 = x squared (x to the power of two) or x*x

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#5 27-09-2005 10:09pm

Delphi91

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Slow coach wrote:

Let x,y be the two numbers.

y = 2*x + 5;

...

That should be y = 2*x + 3!

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#6 28-09-2005 2:30pm

Pherekydes

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Delphi91 wrote:

That should be y = 2*x + 3!

Yeah, spotted that typo. :eek:

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