Răspuns :
3x(1+2+3+............+100)=151500
S=100x101:2=101000:2=5050
3x*5050=151500
3x=151500:5050
3x=30
x=30:3
x=10
V: 30+60+90+........+300=
30(1+2+3+.........100)= 30x5050=151500
3x(1+2+3+............+100)=151500
S=100x101:2=101000:2=5050
3x*5050=151500
3x=151500:5050
3x=30
x=30:3
x=10
V: 30+60+90+........+300=
30(1+2+3+.........100)= 30x5050=151500