SOLUTION: 8x^2-2x=8

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Question 432518: 8x^2-2x=8
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
If 8x^2-2x=8, then;
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4x^2-x=4
4x^2-x-4=0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 4x%5E2%2B-1x%2B-4+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-1%29%5E2-4%2A4%2A-4=65.

Discriminant d=65 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--1%2B-sqrt%28+65+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-1%29%2Bsqrt%28+65+%29%29%2F2%5C4+=+1.13278221853732
x%5B2%5D+=+%28-%28-1%29-sqrt%28+65+%29%29%2F2%5C4+=+-0.882782218537319

Quadratic expression 4x%5E2%2B-1x%2B-4 can be factored:
4x%5E2%2B-1x%2B-4+=+4%28x-1.13278221853732%29%2A%28x--0.882782218537319%29
Again, the answer is: 1.13278221853732, -0.882782218537319. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B-1%2Ax%2B-4+%29