The difference of two positive numbers is 6 and the sum of their squares is 90. Find the numbers.

I know the numbers are 3 and 9, but I just don't know how to go about showing the work.

Thanks!

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- Jul 26th 2013, 01:58 PMcurt26Sequencing problem
The difference of two positive numbers is 6 and the sum of their squares is 90. Find the numbers.

I know the numbers are 3 and 9, but I just don't know how to go about showing the work.

Thanks! - Jul 26th 2013, 02:30 PMPlatoRe: Sequencing problem
- Jul 26th 2013, 02:32 PMadkinsjrRe: Sequencing problem
You just need to translate this into a system of equations.

$\displaystyle x-y=6$

$\displaystyle x^2+y^2=90$

So you can start off:

$\displaystyle x=y+6$

$\displaystyle (y+6)^2+y^2=90$

$\displaystyle (y^2+12y+36) +y^2=90$

$\displaystyle 2y^2+12y-54=0$

Do you see how to take it from here? - Jul 26th 2013, 02:33 PMadkinsjrRe: Sequencing problem
- Jul 26th 2013, 03:16 PMPlatoRe: Sequencing problem