Question

se x + 1/x=3, então o valor de x3 +1/x3é:

Answer 1

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Ola Hanna

x + 1/x = 3

(x + 1/x)³ = x³ + 1/x³ + 3x + 3/x

x³ + 1/x³ = (x + 1/x)³ - 3*(x - 1/x)

x³ + 1/x³ =27 - 3*3 = 27 - 9 = 18

pronto