Q60.If x= 1+ (cube root 5) + (cube root 25), find value of (x cube)-3(x square)-12x+6.

let (cube root 5) = a
x = 1 + a + a^2
putting in
x^3 -3x^2 -12x + 6 we get
an expression in a then substi tute and get teh answer
maybe can try putting x = (a^3-1)/(a-1) to make calculations simpler