SOLUTION: -5x^2+3x+4=0 quadratic equation.

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Question 853891: -5x^2+3x+4=0 quadratic equation.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

-5x^2+3x+4=0

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

x+=+%28-3+%2B-+sqrt%28+89+%29%29%2F%28-10%29+

 


 
Solved by pluggable solver: SOLVE quadratic equation with variable


Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case -5x%5E2%2B3x%2B4+=+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=%283%29%5E2-4%2A-5%2A4=89.

  

  Discriminant d=89 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-3%2B-sqrt%28+89+%29%29%2F2%5Ca.

  

    x%5B1%5D+=+%28-%283%29%2Bsqrt%28+89+%29%29%2F2%5C-5+=+-0.64339811320566

    x%5B2%5D+=+%28-%283%29-sqrt%28+89+%29%29%2F2%5C-5+=+1.24339811320566

    

    Quadratic expression -5x%5E2%2B3x%2B4 can be factored:

  -5x%5E2%2B3x%2B4+=+-5%28x--0.64339811320566%29%2A%28x-1.24339811320566%29

  Again, the answer is: -0.64339811320566, 1.24339811320566.
Here's your graph:

graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-5%2Ax%5E2%2B3%2Ax%2B4+%29