Posted by Karen on .
If the sum of two numbers is 1 and the sum of the cubes of the numbers is 3, what is the sum of the squares of the numbers?

PreCalculus 
bobpursley,
m+n=1
m^3+n^3=1
What if one number is zero, so the other number is .... 
PreCalculus 
Karen,
No, the sum of the cubes is 3 so its m+n=1 m^3+n^3=3

PreCalculus 
bobpursley,
oooppppssss
m+n=1
m^3+n^3=3
If you factor the second equation..
(M+n)(M^2mn+n^2) the first term is 1, so
(m^2+n^2 mn)=3 equation1
but if we square the first equation given
m^2+2mn+n^2 = 1
m^2+n^2+2mn=1 equation2
subtracting equation2 from equation1
mn2mn=2
or 3mn=2
OK, this is not making sense. Check my work, I will try again later.