SOLUTION: x^2-18x-4=0

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Question 401079: x^2-18x-4=0
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
This equation will not factor so we must use the Quadratic Formula (or complete the square):
x+=+%28-%28-18%29+%2B-+sqrt%28%28-18%29%5E2+-+4%281%29%28-4%29%29%29%2F2%281%29
which simplifies as follows:
x+=+%28-%28-18%29+%2B-+sqrt%28324+-+4%281%29%28-4%29%29%29%2F2%281%29
x+=+%28-%28-18%29+%2B-+sqrt%28324+%2B+16%29%29%2F2%281%29
x+=+%28-%28-18%29+%2B-+sqrt%28340%29%29%2F2%281%29
x+=+%2818+%2B-+sqrt%28340%29%29%2F2
x+=+%2818+%2B-+sqrt%284%2A85%29%29%2F2
x+=+%2818+%2B-+sqrt%284%29%2Asqrt%2885%29%29%2F2
x+=+%2818+%2B-+2%2Asqrt%2885%29%29%2F2
x+=+%282%289+%2B-+sqrt%2885%29%29%29%2F2
x+=+%28cross%282%29%289+%2B-+sqrt%2885%29%29%29%2Fcross%282%29
x+=+9+%2B-+sqrt%2885%29
In long form this is:
x+=+9+%2B+sqrt%2885%29 or x+=+9+-+sqrt%2885%29