SOLUTION: Use the quadratic formula to solve the equation; 2x^2-x=-7

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Question 266474: Use the quadratic formula to solve the equation; 2x^2-x=-7
Answer by JBarnum(2146) About Me  (Show Source):
You can put this solution on YOUR website!
2x%5E2-x=-7
2x%5E2-x%2B7=0 A=2 B=-1 C=7
unfortunatly there are no real numbers that "x" can equal, there are however imaginary numbers.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B-1x%2B7+=+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%2A2%2A7=-55.

The discriminant -55 is less than zero. That means that there are no solutions among real numbers.

If you are a student of advanced school algebra and are aware about imaginary numbers, read on.


In the field of imaginary numbers, the square root of -55 is + or - sqrt%28+55%29+=+7.41619848709566.

The solution is

Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B-1%2Ax%2B7+%29