(√15+√5)*√15-5/3*√27

Question

(√15+√5)*√15-5/3*√27

Answer 1

(√15+√5)*√15-5/3*√27 = 15 + √75 - 5√27 /3 = (45 + 3√75 - 5√27)/3 = (45 + √(9*75) - √(25*27))/3 = (45 + √675 - √675)/3 = 45/3 = 15