Question

determinati valoare lui x pentru care 0, (1x ) plus 0, (2x) plus 0, (3x) plus ......plus 0, (9x) egal cu x

Answer 1

0, (1x )+0, (2x) + 0, (3x)+ ...+ 0, (9x)= x

(10+x )/99+(20+x )/99+(30+x )/99+...+(90+x )/99=x
10+20+30+....+90 +9x=99x
10(1+2+3+...+9)=90x
10*9*10/2=90x
450=90x
x=5