Question

If a=1+root7,find the value of -6/a

Answer 1

=-6/1+roots
=6 (1-root7)/(1+root7)(1-root 7)
= 6 (1-root7) /1-7 ------(a^2-b^ in denominator)
=6 (1-root7) /-6
=1-root7/-1
=-1+root7
or
=root 7-1