Problems To Quadratic Equations, HELP

shortys94 · 27-09-2005 04:54PM #1

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

Pherekydes · 27-09-2005 05:21PM

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.

shortys94 · 27-09-2005 08:13PM

aorry but whats ^

eoinf · 27-09-2005 09:11PM

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

Delphi91 · 27-09-2005 11:09PM

Slow coach wrote:

Let x,y be the two numbers.

y = 2*x + 5;

...

That should be y = 2*x + 3!

Pherekydes · 28-09-2005 03:30PM

Delphi91 wrote:

That should be y = 2*x + 3!

Yeah, spotted that typo. :eek:

Problems To Quadratic Equations, HELP

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