SOLUTION: This is confusing for me. Please help. Use the ac test to determine which of the following trinominals can be factored. Find the values of m and n for each trinominal that can b

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: This is confusing for me. Please help. Use the ac test to determine which of the following trinominals can be factored. Find the values of m and n for each trinominal that can b      Log On


   



Question 44818: This is confusing for me. Please help.
Use the ac test to determine which of the following trinominals can be factored. Find the values of m and n for each trinominal that can be factored.
x^2 + 2x -15

Answer by mbarugel(146) About Me  (Show Source):
You can put this solution on YOUR website!
Hello again!
In this case,
a = 1
b = 2
c = -15
Therefore, ac = -15.
Now, the possible pairs of numbers whose product is -15 are:
1 and -15
-1 and 15
5 and -3
-5 and 3
Now, which of these pairs add up to b, which is equal to 2? Clearly, the pair is 5 and -3, as 5 + (-3) = 2. Therefore, this trinomial can be factored. We get that:
x%5E2+%2B+2x+-15+=+%28x%2B5%29%28x-3%29

I hope this helps!
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