SOLUTION: can u help? -8y^3-10y^2-3y=0 thank u!! i need to turn in this homework assignment in um like an hour! :)

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Question 188589: can u help?
-8y^3-10y^2-3y=0
thank u!! i need to turn in this homework assignment in um like an hour! :)
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
-8y^3-10y^2-3y=0
-y*(8y^2 + 10y - 3) = 0
y = 0
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 8x%5E2%2B10x%2B-3+=+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=%2810%29%5E2-4%2A8%2A-3=196.

Discriminant d=196 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-10%2B-sqrt%28+196+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2810%29%2Bsqrt%28+196+%29%29%2F2%5C8+=+0.25
x%5B2%5D+=+%28-%2810%29-sqrt%28+196+%29%29%2F2%5C8+=+-1.5

Quadratic expression 8x%5E2%2B10x%2B-3 can be factored:
8x%5E2%2B10x%2B-3+=+%28x-0.25%29%2A%28x--1.5%29
Again, the answer is: 0.25, -1.5. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+8%2Ax%5E2%2B10%2Ax%2B-3+%29


Sub y for x, the onsite solver uses x.