Question

Cine stie? exercitiul 4

Answer 1

1.
1+2+3+...+2014=2014*2015/2=1007*2015
5¹⁰⁰⁷ˣ²⁰¹⁵=5ⁿ⁺¹⁰⁰⁷
1007x2015=n+1007
n=1007x2015-1007=1007(2015-1)=1007x2014=2028098

2.
2+4+6+....100=2(1+2+3+..+50)=2x50x51/2=2550
7²⁵⁵⁰=7ⁿ⁽ⁿ⁺¹⁾
2550=n(n+1)
2550=50x51
n=50