SOLUTION: For the following quadratic equation, determine the nature of the roots. 5x^2-20x-225=0

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Question 1128717: For the following quadratic equation, determine the nature of the roots.
5x^2-20x-225=0
Found 3 solutions by ikleyn, MathLover1, MathTherapy:
Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.

I can determine not only "the nature" of the roots (the term NONSENSICAL in MATH), but their values, too: they are integer numbers 9 and -5.


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To help the students,  the lessons were created in this site
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Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
5x%5E2-20x-225=0......first simplify, both sides divide by 5
x%5E2-4x-45=0............factor
x%5E2%2B5x-9x-45=0
%28x%5E2%2B5x%29-%289x%2B45%29=0
x%28x%2B5%29-9%28x%2B5%29=0
%28x+-+9%29+%28x+%2B+5%29+=+0
solutions:

%28x+-+9%29+=+0=>x=9

%28x+%2B+5%29+=+0=>x=-5

+graph%28+600%2C+600%2C+-55%2C+55%2C+-55%2C+55%2C+x%5E2-4x-45%29+

Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!
For the following quadratic equation, determine the nature of the roots.
5x^2-20x-225=0
The NATURE of the roots is determined by calculating the DISCRIMINANT, b%5E2+-+4ac. 

In this case, it's 4,900 which signifies that the: