Question

x+[x+1]+[x+2]+.....+[x+30]=1240

 

Answer 1

xin lỗi bạn vì có ai phá nick mình ấy

Answer 2

 

x+[x+1]+[x+2]+.....+[x+30]=1240

(x+x+x+…+x)+(0+1+2+3+…+30)=1240

(x+x+x+…+x)+(30+0)x((30-0):1+1)=1240

(x+x+x+…+x)+(30x31)=1240

Xx31+930=1240

Xx31=1240-930

Xx31=310

X=310:31

X=10

Vậy x=10

Answer 3

 

x+[x+1]+[x+2]+.....+[x+30]=1240

(x+x+x+…+x)+(0+1+2+3+…+30)=1240

(x+x+x+…+x)+(30+0)x((30-0):1+1)=1240

(x+x+x+…+x)+(30x31)=1240

Xx31+930=1240

Xx31=1240-930

Xx31=310

X=310:31

X=10

Vậy x=10