Question

rezolvati ecuatiile:
a) 1+2+3+......+100+x=5050
b) 1 x2x3x......n * x = 1*2*3*4*.....*n(n+1)

Answer 1

a) 1+2+3+...+100+x=5050
100·101:2+x=5050
10100:2+x=5050
5050+x=5050
x=0

b) 1·2·3·4·...·n·x=1·2·3·4·...·n(n+1)
x=n+1