Can you please help me solve?
If M+N=3 and M^2+N^2=6, Find the numerical value for
M(cubed)+N (cubed).
Can you please help me solve?
If M+N=3 and M^2+N^2=6, Find the numerical value for
M(cubed)+N (cubed).
We are given M+N=3 and M^2 + N^2 =6
Factor M^3 + N^3
M^3 + N^3 = (M+N)(M^2 -MN + N^2)
= (M+N)(M^2 + N^2 - MN)
We have all quantities on the right side except MN
To find it, square M + N = 3
M^2 + 2MN + N^2 = 9
Substituting for M^2 + N^2 and solving for MN gives
MN= 3/2
Then
M^3 + N^3 = (M+N)(M^2 + N^2 - MN)
= 3(6 - 3/2)
= 27/2
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