Question

if x - 3/x = 5 then find the value of x^3 - 27/x^3

Answer 1

X-3/x = 5

= X^3 - 27 /X^

= (X)^3 - (3X)^

= (X-3X)^3 + 3 . X . 3/X ( X - 3/X)

= 5^3 + 9 × 5

= 125 + 45

= 170.

Answer 2

x-3/x = 4

(x^3-27/x^3) = (x-3/x)^3

so 4^3 = answer

thus, = 64