(√2-√18)²-30=(√2-√(9*2))²-30=(√2-3√2)²-30=(-2√2)²-30=8-30=22
(6-√2)²-3√32=(36-12√2+2) - 3√(16*2)=38-12√2-12√2=38-24√12
(6-√2)²+3√32=(36-12√2+2) + 3√(16*2)=38-12√2+12√2=38
(√99+√44)*√11=(√(9*11)+√(4*11))*√11=(3√11+2√11)*√11=5√11*√11=5*11=55
(4√6-√54+√24)*√6 = (4√6-√(9*6)+√(4*6))*√6 =
=(4√6-3√6+2√6)*√6 = 3√6*√6=3*6 = 18