X+1/X=3 (X+1/X)^2=X^2+2+1/X^2=9 X^2+1/X^2=7 (X^2+1/X^2)^2=X^4+2+1/X^4=49 X^4+1/X^4=47 X^3+1/x^3=(X+1/X)(x^2-x1/x+1/x^2)=3X(7-1)=18(X^4+1/X^4)(X+1/X)=X^5+!/X^5+X^3+1/X^3=47x3=141 X^5+!/X^5=141-18=123
123