Question

pls solve this question

Answer 1

conjugate x value multiple 2+√3 both numerator and denominator

denominator (2-√3)(2+√3)=4-3=1
so x=2+√3

x^3=(2+√3)^3=8+3√3+6√3(2+√3
=8+3√3+12√3+18
=26+15√3

2x^2=2(2+√3)^2=2(4+3+4√3)=2(7+4√3)
=14+8√3

7x=14+7√3

finally
26+15√3-14-8√3-14-7√3+5
=3