SOLUTION: The sum of the squares of two integers is 80 and one number is twice the other. What are the numbers?

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Question 529769: The sum of the squares of two integers is 80 and one number is twice the other. What are the numbers?
Answer by swincher4391(1107) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + y^2 = 80
x = 2y
(2y)^2 + y^2 = 80
4y^2 + y^2 = 80
5y^2 = 80
y^2 = 16
y=4 [or -4]
So x = 2(4)
x = 8 [or -8]
4 and 8 are your answers. But if you think about it, -4 and -8 work too. Not sure how advanced your class is, but yeah, think about it. -4^2 + -8^2 = 16 + 64 = 80 and -4 * 2 = -8.