Question

Aflati valoare lui x din relatia : 1ori x+2ori x+.....+20ori x=630

Answer 1

1×X + 2×X +...+ 20×X = 630

X(1 + 2 +...+20) = 630

X ( 20×21:2) = 630

X(10×21) = 630

X × 210 = 630

X = 630 : 210

X = 3