(1)√75-√54+√96-√108;
=5√3-3√6+4√6-6√3
=√6-√3
(2)(1/2)(√2+√3)-(3/4)(√2+√27).
=(1/2)√2+(1/2)√3-(3/4)√2-(3/4)3√3
=(-1/4)√2-(7/4)√3