Question

( x +1 ) + ( x + 2) +...+ (x +10) = 165

Answer 1

( x + 1 ) + ( x + 2 ) + ... + ( x + 10 ) = 165

10 * x + 55 = 165

10 * x = 165 - 55

10 * x = 110

=> x = 110 : 10

=> x = 11 

 Vậy x = 11 

Answer 2

( x +1 ) + ( x + 2) +...+ (x +10) = 165

=> 10x + (1 + 2 + 3 + ... + 10) = 165

=> 10x + 55 = 165

=> 10x = 110

=> x = 11

Answer 3

ta phá ngoặc

x+1+x+2+x+3+x+4+x+5+x+6+x+7+x+8+x+9+x+10=165

10.x+(1+2+3+4+5+6+7+8+9+10)=165

10.x+55=165

10.x=165-55

10.x=110

x=110:10

x=11

Answer 4

( x + 1 ) + ( x + 2 ) + ... + ( x + 10 ) = 65

10 x x + 55 = 165

10 x x = 165 - 55

10 x x = 110 

x = 110 : 10

x = 11