Question

I) If a+1/a=4;find 1)a2+1/a2 2)a4+1/a4 3)a3+1/a3

II) If x+1/x=2; then show that; x2+1/x2=x3+1/x3=x4+1/x4

III) If 2x-3y=10 and xy=16; find the value of 8x3-27y3

Answer 1

I 1) 14
2) 194
3) 52

III) 3880