SOLUTION: y+5=x 5x^2+y^2=81

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Question 353156: y+5=x
5x^2+y^2=81
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1. y%2B5=x
2.5x%5E2%2By%5E2=81
From eq. 1,
x%5E2=%28y%2B5%29%5E2
Substitute into eq. 2,
5%28y%2B5%29%5E2%2By%5E2=81
5%28y%5E2%2B10y%2B25%29%2By%5E2=81
5y%5E2%2B50y%2B125%2By%5E2=81
6y%5E2%2B50y%2B44=0
3y%5E2%2B25y%2B22=0
%283y%2B22%29%28y%2B1%29=0
Two solutions:
3y%2B22=0
3y=-22
highlight%28+y=-22%2F3%29
Then from eq. 1,
x=-22%2F3%2B5
x=-22%2F3%2B15%2F3
highlight%28x=-7%2F3%29
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y%2B1=0
highlight_green%28+y=-1%29
Then from eq. 1,
x=-1%2B5
highlight_green%28+x=4%29
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(4,-1) and (-7%2F3,-22%2F3)
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