a) 2√1440-4√2*(√180-3√8) =
= 24√10-4√2*(6√5-6√2) =
= 24√10-24√10+48 =
= 48
b) 2√1215+3√5*(2√80-√50 ) =
= 18√15+3√5*(8√5-5√2) =
= 18√15+120-15√10
c) √54*(√960√27(√98-√18))=
= √54*(4√6-3√3*(7√2-3√2) =
= √54*(4√6-3√3*4√2) =
=√54*(4√6-12√6) =
=√54*(-8√6) =
=-3√6*8√6 =
=-3*6*8 = -144
