Question

X³-2x²-7x+8 when x=2+√3

Answer 1

x-2=√3

squaring on both sides

x square +4-4x=3

x square -4x+1=0

lines are not coming

so, i leave gap for long division

first line is quotient which is another 2 root

                                 x+2

x square - 4x +1           x cube - 2 x square -7x +8

                                    x cube - 4 x square + x

                                                  2 x square - 8x + 8

                                                   2 x square - 8 x +2

                                                                                 4

hence , 2+ √3 is not a root of the following equation

hope , i cannot understand the question what you have asked

          i tried my level best

           hope,this help u