SOLUTION: x^2-4x=6

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Question 401068: x^2-4x=6
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
When solving quadratic equations you want one side to be zero. So we start by subtracting 6 from each side:
x%5E2-4x-6=0
This equation will not factor so we must use the Quadratic Formula (or complete the square):
x+=+%28-%28-4%29+%2B-+sqrt%28%28-4%29%5E2-4%281%29%28-6%29%29%29%2F2%281%29
which simplifies as follows:
x+=+%28-%28-4%29+%2B-+sqrt%2816-4%281%29%28-6%29%29%29%2F2%281%29
x+=+%28-%28-4%29+%2B-+sqrt%2816%2B24%29%29%2F2%281%29
x+=+%28-%28-4%29+%2B-+sqrt%2840%29%29%2F2%281%29
x+=+%284+%2B-+sqrt%2840%29%29%2F2
x+=+%284+%2B-+sqrt%284%29%2Asqrt%2810%29%29%2F2
x+=+%284+%2B-+2%2Asqrt%2810%29%29%2F2
x+=+%282%282+%2B-+sqrt%2810%29%29%29%2F2
x+=+%28cross%282%29%282+%2B-+sqrt%2810%29%29%29%2Fcross%282%29
x+=+2+%2B-+sqrt%2810%29
In long form this is:
x+=+2+%2B+sqrt%2810%29 or x+=+2+-+sqrt%2810%29