(akar3+akar7) (akar3-akar7) bagi 2akar5+3akar3

jawab

(√3  + √7)(√3 - √7)/ (2√5 + 3√3) =

= (3 - 7)/(2√ 5   + 3√3) 

= - 4/ (2√5 + 3√3)

= - 4(2√5 - 3√3)/ (2√5 + 3√3)(2√5 - 3√3) 

= - 4(2√5 - 3√3)/(20 - 27)

=  4/7 (2√5 - 3/√3)