(x+1)+(x+2)+(x+3)+….+(x+10)=57 giúp mình với iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

0 bình luận về “(x+1)+(x+2)+(x+3)+….+(x+10)=57 giúp mình với iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii”

1. $\text{(x + 1) + (x + 2) + (x + 3) + … + (x + 10) = 57}$

   $\text{x × 10 + (1 + 2 + 3 + … + 10) = 57}$
   $\text{x × 10 + 55 = 57}$
   $\text{x × 10 = 57 – 55}$
   $\text{x × 10 = 2}$
   $\text{x = 2 : 10}$
   $\text{x = 0,2}$

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2. (x+1)+(x+2)+(x+3)+….+(x+10) = 57

   ⇔ x + 1 + x + 2 + x + 3 +…..+ x + 10 = 57

   ⇔ 10x + ( 1 + 2 + …… + 10 ) = 57

   ⇔ 10x + 55 = 57

   ⇔ 10x = 2

   ⇒ x = 0,2

    

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