SOLUTION: my problem are plz help me i need to see the work i need them solved by tonight plz 1) x^2-8x+15=0 2) x^2+2x-6=0 3) 2x^2+3x-5=0 4) 2x^2+7x+6=0 4) x^2-4x+5=

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson  -> Lesson -> SOLUTION: my problem are plz help me i need to see the work i need them solved by tonight plz 1) x^2-8x+15=0 2) x^2+2x-6=0 3) 2x^2+3x-5=0 4) 2x^2+7x+6=0 4) x^2-4x+5=      Log On


   

Question 247920: my problem are plz help me i need to see the work
i need them solved by tonight plz
1) x^2-8x+15=0

2) x^2+2x-6=0

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

4) 2x^2+7x+6=0

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

5) x^2-10x+28=0
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
1) x^2-8x+15=0
(x-3)*(x-5) = 0
x = 3, x = 5
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2) x^2+2x-6=0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B2x%2B-6+=+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=%282%29%5E2-4%2A1%2A-6=28.

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

x%5B1%5D+=+%28-%282%29%2Bsqrt%28+28+%29%29%2F2%5C1+=+1.64575131106459
x%5B2%5D+=+%28-%282%29-sqrt%28+28+%29%29%2F2%5C1+=+-3.64575131106459

Quadratic expression 1x%5E2%2B2x%2B-6 can be factored:
1x%5E2%2B2x%2B-6+=+%28x-1.64575131106459%29%2A%28x--3.64575131106459%29
Again, the answer is: 1.64575131106459, -3.64575131106459. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B2%2Ax%2B-6+%29

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x = -1 ± sqrt(7)
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3) 2x^2+3x-5=0
do these like the ones above. If you can't factor them, use the quadratic equation. It always works.
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4) 2x^2+7x+6=0
4) x^2-4x+5=0
5) x^2-10x+28=0