SOLUTION: This problem is not in the book nor can I find one like it to show me what to do, my instructor made i up I think. x^2 + 8x (> or = ) 0 I am not sure where to start on this

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: This problem is not in the book nor can I find one like it to show me what to do, my instructor made i up I think. x^2 + 8x (> or = ) 0 I am not sure where to start on this       Log On


   

Question 63601This question is from textbook
: This problem is not in the book nor can I find one like it to show me what to do, my instructor made i up I think.
x^2 + 8x (> or = ) 0
I am not sure where to start on this
thanks This question is from textbook

Answer by sarahschober(35) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B8x%2B0+=+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=%288%29%5E2-4%2A1%2A0=64.

Discriminant d=64 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-8%2B-sqrt%28+64+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%288%29%2Bsqrt%28+64+%29%29%2F2%5C1+=+0
x%5B2%5D+=+%28-%288%29-sqrt%28+64+%29%29%2F2%5C1+=+-8

Quadratic expression 1x%5E2%2B8x%2B0 can be factored:
1x%5E2%2B8x%2B0+=+%28x-0%29%2A%28x--8%29
Again, the answer is: 0, -8. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B8%2Ax%2B0+%29