Question

Afla valoarea lui x din expresia x+(1+2+3+4+...+49)=1625

Answer 1

x+(1+2+3+4+...+49)=1625
Dar 1+2+3+4+...+49 = 50x49/2= 25x49 = 1225
Atunci x = 1625-(1+2+3+4+...+49) = 1625-1225 = 400
x = 400

Answer 2

x+(1+2+3+4,,,+49)=1625                       
1+2+3+4+,,,+49=50*49/2
25*49=1225
x=1625-(1+2+3+4,,,+49)=1625-1225=400
x=400