Question 890599: `If x–y=7 and xy=6 then find the value of x^4+1/x^4
Answer by JulietG(1812)   (Show Source):
You can put this solution on YOUR website! If xy = 6, what are the possibilities?
x=6, y=1
x=3, y=2
x=2, y=3
x=1, y=6
and the negatives of the above pairs.
None of those pairs fits the equation x-y=7
Is it perhaps supposed to be x+y=7? In that case, xy can either be 6,1 or 1,6.
Using 6,1...
 + = 1296
Using 1,6...
 + = 2
.
Please repost if the assumptions are incorrect.
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