SOLUTION: "find all integers m for which y^2+my+50 can be factored?"

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Question 183211: "find all integers m for which y^2+my+50 can be factored?"
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First, multiply the first coefficient 1 and the last term 50 to get 50. Now list the factors of 50




Factors of 50:
1,2,5,10,25,50
-1,-2,-5,-10,-25,-50


Note: list the negative of each factor. This will allow us to find all possible combinations.


These factors pair up and multiply to 50.
1*50
2*25
5*10
(-1)*(-50)
(-2)*(-25)
(-5)*(-10)

Now add up each paired factor (ie 1+50=51, 2+25=27, etc..):


First NumberSecond NumberSum
1501+50=51
2252+25=27
5105+10=15
-1-50-1+(-50)=-51
-2-25-2+(-25)=-27
-5-10-5+(-10)=-15



All of the numbers in the last column are possible values for the value of "m". Remember, you can only factor ax%5E2%2Bbx%2Bc only if the factors of ac add to "b"


So the possible values for "m" are: 51, 27, 15, -51, -27, -15


Note: all of these values of "m" are straight from that third column.


This means that the following quadratics are factorable:

y%5E2%2B51y%2B50,

y%5E2%2B27y%2B50,

y%5E2%2B15y%2B50,

y%5E2-51y%2B50,

y%5E2-27y%2B50, and

y%5E2-15y%2B50