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What two numbers add to 19 and multiply to 60

User Jimmetry
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2 Answers

4 votes
I did this in a different way, not using algebra

I started with the factors of 60
1x60
2x30
3x20
4x15 which are the two numbers that added up to 19
User Brian Bi
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3 votes

x;\ y-the\ numbers\\\\\left\{\begin{array}{ccc}x+y=19&|subtract\ y\ from\ both\ sides\\xy=60\end{array}\right\\\left\{\begin{array}{ccc}x=19-y&(1)\\xy=60&(2)\end{array}\right\\\\subtitute\ (1)\ to\ (2)\\\\(19-y)y=60\\19y-y^2=60\ \ \ \ |subtract\ 60\ from\ both\ sides\\-y^2+19y-60=0\\-y^2+15y+4y-60=0\\-y(y-15)+4(y-15)=0\\(y-15)(-y+4)=0\iff y-15=0\ or\ -y+4=0\\\\\boxed{y=15\ or\ y=4}


subtitute\ the\ value\ of\
User Naz Mir
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