A positive number is divided into two parts such that the sum of the square of the two parts is 20.The square of the larger part is 8 times the smaller part.Taking x as the smaller part of the two parts,find the number
@perl @mathslover

Question

A positive number is divided into two parts such that the sum of the square of the two parts is 20.The square of the larger part is 8 times the smaller part.Taking x as the smaller part of the two parts,find the number
@perl @mathslover

anonymous · Answer

The two parts' square sums to 20. The only squares that some to 20 are 4 and 16. The smaller part (x) is therefore 2. This is confirmed by the fact that 2=16/8. So the square of the larger part is 8 times x. Since the number was divided to get the two parts we must multiply to find the number. 2 x 4=8 so the number is 8.

aaronandyson · Answer

???

perl · Answer

Let x = smaller number, y = bigger number
sum of the squares of the numbers is 20, 
bigger number squared is 8 times smaller
x^2 + y^2 = 20
y^2 = 8*x

perl · Answer

by substitution
x^2 + 8x = 20
x^2 + 8x - 20 = 0 

( x - 2) ( x + 10) = 0

x = 2, -10 

remember x is positive, so x is 2

aaronandyson · Answer

What?

aaronandyson · Answer

@perl

alekos · Answer

He's given you the answer.

aaronandyson · Answer

The book says it 3 and 17 :S

alekos · Answer

are you sure that s the right Answer? 
Have you got a screen shot of the question?

mathmate · Answer

@AaronAndyson 
Perhaps you want to check if the answer corresponds to the right question.

perl · Answer

I'm not sure how your book got that answer. You can verify my work here, they did the same exact thing http://www.algebra.com/algebra/homework/word/numbers/Numbers_Word_Problems.faq.question.887984.html

alekos · Answer

Looks like the cat's got your tongue

aaronandyson · Answer

Yes the question number correspond with the answer number

alekos · Answer

Well it must be a typo

mathmate · Answer

@AaronAndyson 
Thank you for checking.  I believe there is a mistake in the answer, or the wrong page, or whatever.

The question says: "the sum of the square of the two parts is 20"
The square of 17 is 289, already exceeds 20, while the $sum$ of the two parts is 20.  So the answer cannot correspond to the posted question...unless there is a typo in the question itself.
I think your teacher is the only one who can sort this out, assuming there is no typo on your part.

aaronandyson · Answer

Nevertheless,Can you explain my new question in DETAIL?