Question

If x2 +2=33 +33, then show that: 3x(x2 + 3) =8​

Answer 1

Answer:

x = 3+3^(1/3)+3^(2/3)

=> x-3 = 3^(1/3)+3^(2/3)

Taking cube both sides and expand it we get

(x-3)^3 = {3^(1/3) + 3^(2/3)}^3

=>x^3 -9x^2 + 27x -27 = 3 +9×3^(1/3) +9×3^(2/3) + 9

=> x^3–9x^2+27x-27 = 9{3^(1/3)+3^(2/3)}+12

=> x^3–9x^2+27x-27 = 9(x-3)+12

=> x^3–9x^2+27x-27= 9x-27+12

=> x^3–9x^2+27x-9x-27+27–12=0

=> x^3–9x^2+18x-12 =0