Question

plz help me solve these questions

Answer 1

(III)   x = 3-2√2
       x² = (3-2√2)²
     ∴x² = 3²- 2×3×2√2 +(2√2)²
       x² = 9 -12√2+8
       x²= 17 -12√2
    ∵ x²+1/x² = 17-12√2 +1 / 17-12√2
                   = 18-12√2 / 17-12√2
                   = (18-12√2)(17+12√2) / (17-12√2)(17+12√2)
                   = 18(17+12√2)-12√2(17+12√2) / (17)²-(12√2)²
                   = 306+216√2-204√2-288 / 289-288
                   = 306-288+12√2 / 1
                   = 18 + 12√2
∴ the answer is 18+12√2

SORRY I DON`T KNOW THE ANSWER OF (II).

BUT I HOPE THE (III) IS HELPFUL TO YOU......

THANK YOU!!!!