Giải thích:
`\text\{( x + 1 ) + ( x + 2 ) + ( x + 3 ) + ... + ( x + 100 ) = 2 . 5 ^ 3 . 23}`
`\text\{⇒ (x+x+x+...+x)+(1+2+3+...+100)=5750}`
`\text\{⇒ 100x + [(100+1).100:2]=5750}`
`\text\{⇒ 100x + 5050=5750}`
`\text\{⇒ 100x=5750-5050}`
`\text\{⇒ 100x=700}`
`\text\{⇒ x = 700 : 100 = 7}`