SOLUTION: Identify the solutions to the system of equations: x2 + y2 = 25 16x2 + 25y2 = 400

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Question 43748: Identify the solutions to the system of equations:
x2 + y2 = 25
16x2 + 25y2 = 400
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + y^2 = 25
y^2 = 25 - x^2
so:
16x^2 + 25y^2 = 400
16x^2 + 25(25 - x^2) = 400
16x^2 + 625 - 25x^2 = 400
-9x^2 = -225
x^2 = 25
x = +-5
Plug:
x^2 + y^2 = 25 and x^2 + y^2 = 25
5^2 + y^2 = 25 and (-5)^2 + y^2 = 25
y^2 = 0 and y^2 = 0
y = 0 and y = 0
(5,0) and (-5,0)