if x+1/x=7, then find the value of x^3+1/x^3. plz give me the solution
jashangunpreet:
anyone plz give me solution
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Sol:
If x+1/x =7 then find the value of x3+1/x3
x + 1/x = 7
Cubing on both sides,
(x + 1/x)3 = (7)3
x3 + 1/x3 + 3 × x × 1/x × (x + 1/x) = 343
x3 + 1/x3 + 3(7) = 343
x3 + 1/x3 + 21 = 343
x3 + 1/x3 = 343 - 21
x3 + 1/x3 = 322
Therefore, the value of (x + 1/x)3 is 322.
If x+1/x =7 then find the value of x3+1/x3
x + 1/x = 7
Cubing on both sides,
(x + 1/x)3 = (7)3
x3 + 1/x3 + 3 × x × 1/x × (x + 1/x) = 343
x3 + 1/x3 + 3(7) = 343
x3 + 1/x3 + 21 = 343
x3 + 1/x3 = 343 - 21
x3 + 1/x3 = 322
Therefore, the value of (x + 1/x)3 is 322.
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