(x+1)+(x+2)+........+(x+9)+(x+10)=5
=>x+1+x+2+....+x+9+x+10=5
=>(x+x+x+...+x+x)+(1+2+3+4+5+6+7+8+9+10)=5
=>10x+55=5
=>10x=5-55
=>10x= -50
=>x= -50:10
=>x= -5
tick nha
(x+1)+(x+2)+.............................+(x+9)+(x+10)=5
10x+(1+2+...+9+10) =5
10x+55 =5
10x =5-55
10x =-50
x =-50:10
x =-5