1)
a) 3*sqrt(25/16)-1=3*5/4-1=15/4-4/4=11/4
б) sqrt(2.5)*sqrt(10)=5
в) sqrt(0.72/8)=sqrt(0.09)=0.3
г) sqrt(3^4*2^6)=3^2*2^4=9*16=144
2) 5sqrt48-2sqrt75=20sqrt3-10sqrt3=10sqrt3
б) (3sqrt2+sqrt18)sqrt2=6+6=12
в) (4-sqrt5)^2=16-8sqrt5+5=21-8sqrt5
3) 15sqrt2=sqrt450
-8sqrt3=-sqrt192
4) sqrt(25-10a+a^2)
a^2-10a+25=0
D=100-100=0
x=-b/2a=5
sqrt(x-5)^2=x-5
6) 2/(3sqrt5+1)-2/(3sqrt5-1)=(6sqrt5-2-6sqrt5-2)/(45-1)=-4/44=-1/11