Question

x-1/x=5 then find x³-1/x³

Answer 1

hey your ans is here
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given

x-1/x=5
x3-1/x3=?
now using identity
(x-1/x)^3=x3-1/x3-3(x-1/x)
(5)3=x3-1/x3-3(5)
125=x3-1/x3-15
125+15=x3-1/x3
140=x3-1/x3
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