1/(√3-√2)+1/(√4-√3)+....+1/(√10-√9)=
=(√3+√2)/(√3-√2)(√3-√2)+(√4+√3)/(√4-√3)(√4+√3)+....+(√10+√9)/(√10-√9)(√10+√9)=
=(√3+√2)/(3-2)+(√4+√3)/(4-3)+....+(√10+√9)/(10-9)=
=√3+√2+√4+√3+....+√10+√9=
=√2+2√3+2√4+2√5+2√6+2√7+2√8+2√9+√10=
=√2+2(√3+√4+√5+√6+√7+√8+√9)+√10=
=√2+2(√3+√5+√6+√7+√8)+√10+4+6=
=√2+4√2+2(√3+√5+√6+√7)+√10+10=
=5√2+2√3(1+√2)+√5(2+√2)+2√7+10 ≈38,36..
2.1/(√5-2)=(√5+2)/(√5-2)(√5+2)=(√5+2)/(5-4)=√5+2
1/(√5-2) > √5
3. x²-3x+2=0
x²-2x-x+2=0
x(x-2)-(x-2)=0
(x-2)(x-1)=0
x-2=0 x=2
x-1=0 x=1
4) diagonala cub =√(1+1+1)=√3 m
