a)(2√3+√5)√3−√60
=2√3.√3+√5.√3−√60
=2√32+√15−√4.15
=2.3+√15−2√15
=6−√15
b)
(5√2+2√5)√5−√250
=5√2.√5+2√5.√5−√250
=5√10+2√52−√25.10
=5√10+2.5−5√10
=10
c)
(√28−√12−√7)√7+2√21
=(√4.7−√4.3−√7)√7+2√21
=(2√7−2√3−√7)√7+2√21
=2√7^2−2√21−√7^2+2√21
=2.7−7=14−7=7
d)
(√99−√18−√11)√11+3√22
=(√9.11−√9.2−√11)11+3√22
=(3√11−3√2−√11)√11+3√22
=3√11^2−3√22−√11^2+3√22
=3.11−11=33−11=22
cho xin hay nhất và 1 tick