1
a)5-10√2+2-10√(5-√2)²=7-10√2-10(5-√2)=7-10√2-50+10√2=-43
b)4+4√5+5+4√(√5-2)²=9-4√5+4(√5-2)=9-4√5+4√5-8=1
2
2/(√31-√29)=2(√31+√29)/(√31-√29)(√31+√29)=2(√31+√29)/(31-29)=√31+√29
4/(√27-√23)=4(√27+√23)/(√27-√23)(√27+√23)=4(√27+√23)/(27-23)=√27+√23
√31>√√27 U √29>√23⇒√31+√29>√27+√23⇒2/(√31-√29)>4/(√27-√23)
3
2√6=√24⇒4<2√6<5<br>4
x=√(4-2√3)-√(4+2√3)=√(√3-1)²-√(√3+1)√=√3-1-√3-1=-2
a)x²=(-2)²=4
b)ч-целое
5
(2√u-√v)(2√u+√v)/(2√u-√v) +(√u-√v)²/(√u-√v)=2√u+√v+√u-√v=3√u
u=1/25 3*√(1/25)=3*1/5=3/5=0,6