Question

afla sumele:a)3+5+7+9+11+13+15+17=?b)1+2+3+4....96+97+98+99+100=?

Answer 1

a)3+5+7+9+11+13+15+17=
=8+7+9+11+13+15+17
=15+9+11+13+15+17
=24+11+13+15+17
=35+13+15+17
=48+15+17
=63+17
=80
b) 1+2+3+...98+99+100=S
rezolvam prin suma lui gauss
S=1+2+3+...+98+99+100
S=100+99+98+...+3+2+1
2×S=101+101+101+...101+101
2×S=101×100(pentru ca sunt 100 de termeni)
2×S=10100
S=10100:2
S=5050
Sper ca te-am ajutat!