Question

x+(x+1)+(x+2)+...+(x+30)=1240

Answer 1

x+(x+1)+(x+2)+…+(x+30)=1240

=>x+x+1+x+2+x+3+…+x+30=1240

=>x+x+x+…+x+1+2+3+…+30=1240

Từ 1->30 có: (30-1):1+1=30(số)

=>31.x+(30+1).30:2=1240

=>31.x+31.15=1240

=>31.x+465=1240

=>31.x=1240-465

=>31x=775

=>x=775:31

=>x=25            

Answer 2

Ta có :

\(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)

\(\Rightarrow x+x+1+x+2+x+3+...+x+30=1240\)

\(\Rightarrow x+x+x+...+x+1+2+3+...+30=1240\)

Answer 3

vẫn ngu và tỷ lệ nợ xấu