SOLUTION: The squares of two numbers add to 360. The second number is half the value of the first number squared. What are the numbers?

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Question 1060510: The squares of two numbers add to 360. The second number is half the value of the first number squared. What are the numbers?

Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
Let the first number be x
Let the 2nd number be y
x%5E2+%2B+y%5E2+=+360+ (1) (the squares of two numbers add to 360)
+y+=+%281%2F2%29x%5E2+ (2) (the 2nd number is half the value of the first number squared)
Re-arranging (2) gives:
+x%5E2+=+2y+
Now plug in 2y for x%5E2%7D%7D+in+%281%29%3A%0D%0A%0D%0A%7B%7B%7B+2y+%2B+y%5E2+=+360+
++y%5E2+%2B2y+-360+=+0+
+%28y-18%29%28y%2B20%29+=+0+
+y=18+ or +y=-20+

For real answers, we only need to consider y=18, the y=-20 answer will lead to imaginary values of x (which is considered after the real answer section).

For y = 18, using (1), +x%5E2+=+360+-+18%5E2+
+x%5E2+=+36+
+x+=+6 or +x=-6 (both values of x work)
So the 2 possible real answers are:
++x+=+6+ and +y+=+18+
and +x+=+-6++ and +y+=+18+

If imaginary solutions are allowed, then the +y=-20+ answer from our factoring must be considered.
If +y=-20+ then +x%5E2+=+-40+ (from (2))
This means +x=+i%2Asqrt%2840%29+ or +x+=+-i%2Asqrt%2840%29+
Plugging in these values of x into (1) and (2), with y=-20, show they work.
Additional 2 answers if imaginary solutions are acceptable:
+x=-i%2Asqrt%2840%29+ and +y=-20+
and +x=i%2Asqrt%2840%29+ and +y=-20+