SOLUTION: Give exact and approximate solutions to 3 decimal places. x^2+16x+64=9 Please help me solve.

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Question 262300: Give exact and approximate solutions to 3 decimal places.
x^2+16x+64=9
Please help me solve.
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
step 1 - subtract 9 to get
x%5E2+%2B16x+%2B55+=+0
step 2 - using quadratic, we get
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
which is
x+=%28-16+%2B-sqrt%28256+-+4%2A1%2A55%29%29%2F2
and then
x+=+%28-16+%2B-sqrt%2836%29%29%2F2
which becomes
x+=+%28-16+%2B-+6%29%2F2
we get two answers:
x = -11
x = -5