orion8105 30.23
1)0,5sqrt12-3sqrt27+0,4sqrt75=0,5sqrt3*4-3sqrt3*9+0,4sqrt25*3= 
0,5*2sqrt3-3*3sqrt3+0,4*5sqrt3=sqrt3-9sqrt3+2sqrt3= -6sqrt3
2)2,5sqrt28b+2/3sqrt63b-10sqrt0,07b=2,5sqrt4*7+2/3sqrt9*7-10sqrt7/100=
=2,5*2sqrt7+2/3*3sqrt7-10*1/10sqrt7=5sqrt7+2sqrt7-sqrt7=6sqrt7
3)sqrt81a^7-5a^3sqrt a+6/asqrt a^9=9a^3sqrt a-5a^3sqrt a+6/a*a^4sqrta=
=4a^3sqrt a +6a^w3sqrt a=10a^3sqrt a
30.26
1) (3sqrt2+1)(sqrt8-2)=(3sqrt2+1)(2sqrt2-2)=
=3sqrt2*2sqrt2-3sqrt2*2+2sqrt2-2= 12-6sqrt2+2sqrt2-2=10-4sqrt2
2)(3-2sqrt7)^2+(3+2sqrt7)^2= 9-12sqrt7+28+9+12sqrt7+28=18+56=74
3)(10-4sqrt6)(2+sqrt6)^2=(10-4sqrt6)(10+4sqrt6)=100-96=4
4)(sqrt(9-4sqrt2)+sqrt(9+4sqrt2))^2= (sqrt(2sqrt2-1)^2+sqrt(2sqrt2+1)^2)^2=
=(2sqrt2-1+2sqrt2+1)^2=(4sqrt2)^2=32
30.28
1)(a-b)/sqrt11b-sqrt11a=
 = -(b-a)(sqrt11b+sqrt11a)/(sqrt11b-sqrt11a)(sqrt11b+sqrt11a)=
= -(b-a)(sqrt11b+sqrt11a)/11(b-a)= -(sqrt11b+sqrt11a)/11
2)(2a+10sqrt2ab+25b)/6a-75b=(sqrt2a+5sqrtb)^2/3(2a-25b)=
=(sqrt2a+5sqrtb)^2/3(sqrt2a-5sqrtb)(sqrt2a+5sqrtb)=
=(sqrt2a+5sqrtb)/3(sqrt2a-5sqrtb)
3)(a-2sqrta+4)/asqrta+8=(a-2sqrta+4)/sqrta^3+8=
=(a-2sqrta+4)/(sqrta+2)(a-2sqrta+4)= 1/a-2sqrta+4
30.30
1)sqrt5/sqrt5-2=sqrt5(sqrt5+2)/(sqrt5-2)(sqrt5+2)=(5+2sqrt5)/5-4=5+2sqrt5
2)8/sqrt10-sqrt2=8(sqrt10+sqrt2)/(sqrt10-sqrt2)(sqrt10-sqrt2)=
=8(sqrt10-sqrt2)/10-2=sqrt10-sqrt2
3)9/sqrtx+sqrty=9(sqrtx-sqrty)/(sqrtx+sqrty)(sqrtx-sqrty)=9(sqrtx-sqrty)/x-y
4)(2-sqrt2)/2+sqrt2=(2-sqrt2)(2-sqrt2)/(2+sqrt2)(2-sqrt2)=(2-sqrt2)^2/4-2=
=(2-sqrt2)^2/2