SOLUTION: 18x^2 + 9x +1=0 answer:x= -1/3 or -1/6 need a full break down of how my book got this answer

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: 18x^2 + 9x +1=0 answer:x= -1/3 or -1/6 need a full break down of how my book got this answer      Log On


   

Question 184641: 18x^2 + 9x +1=0

answer:x= -1/3 or -1/6

need a full break down of how my book got this answer
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
18x^2 + 9x +1 = 0
;
they used the quadratic formula, namely:
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
;
In your equation a=18, b=9, c=1, so we have:
x+=+%28-9+%2B-+sqrt%28+9%5E2+-+4+%2A+18+%2A+1+%29%29%2F%282%2A18%29+
:
x+=+%28-9+%2B-+sqrt%2881+-+72+%29%29%2F%2836%29+
:
x+=+%28-9+%2B-+sqrt%289%29%29%2F%2836%29+
Two solutions;
x+=+%28-9+%2B+3%29%2F%2836%29+
x = %28-6%29%2F36
x = -1%2F6
and
x+=+%28-9+-+3%29%2F%2836%29+
x = %28-12%29%2F36
x = -1%2F3
:
:
Could you follow this OK?