SOLUTION: use the quadratic formula to solve for this equation: 2a^2-46a+252=0 i dont get that can you please help :)

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Question 172064: use the quadratic formula to solve for this equation: 2a^2-46a+252=0
i dont get that can you please help :)
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
use the quadratic formula to solve for this equation: 2a^2-46a+252=0
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a^2 - 23a + 126 = 0 Divide it by 2
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-23x%2B126+=+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=%28-23%29%5E2-4%2A1%2A126=25.

Discriminant d=25 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--23%2B-sqrt%28+25+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-23%29%2Bsqrt%28+25+%29%29%2F2%5C1+=+14
x%5B2%5D+=+%28-%28-23%29-sqrt%28+25+%29%29%2F2%5C1+=+9

Quadratic expression 1x%5E2%2B-23x%2B126 can be factored:
1x%5E2%2B-23x%2B126+=+%28x-14%29%2A%28x-9%29
Again, the answer is: 14, 9. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-23%2Ax%2B126+%29

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The solver uses x, just make that a
a = 9
a = 14