SOLUTION: find the vertex of the parabola: x^2 + 4x + 8y - 20 =0

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Question 64721: find the vertex of the parabola: x^2 + 4x + 8y - 20 =0
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2+%2B+4x+%2B+8y+-+20+=+0
first put this in the form
y+=+ax%5E2+%2B+bx+%2B+c
The vertex is at (%28-b%29+%2F+2a , y)
-8y+=+x%5E2+%2B+4x+-+20
y+=+%28-1%2F8%29x%5E2+%2B+4x%2F%28-8%29+-20+%2F+%28-8%29
%28-b%29+%2F+2a+=+%281%2F2%29+%2F+%28-1%2F4%29
%28-b%29+%2F+2a+=+-2
solve for y
x%5E2+%2B+4x+%2B+8y+-+20+=+0
%28-2%29%5E2+%2B+4%28-2%29+%2B+8y+-+20+=+0
4+-+8+%2B+8y+-+20+=+0
8y+=+24
y+=+3
The vertex is at (-2 , 3)