Răspuns:
[√(1*2)]+[√(2*3)]+.....+[√(50*51)]=1275 (A)
Explicație pas cu pas:
1<√(1*2)<2=>[√(1*2)]=1
2<√(2*3)<3=>[√(2*3)]=2
.........................................
50<√(50*51)<51=>[√(50*51)]=50
[√(1*2)]+[√(2*3)]+.....+[√(50*51)]=
=1+2+3+.........+50
=50*51/2
=25*51
=1275 (Adevărat)
