( x+1) + ( x+4 ) + ( x+7) +( x+ 10 ) + ... + ( x+ 28) = 155
=> ( x + x + x + x + ...+x ) + ( 1 + 4 + 7 + 10 +.. 28 ) = 155
= 10x + 145 = 155
=> 10x = 155 - 145
= 10x = 10
=> x = 10 : 10
x = 1
(x+1)+(x+4)+(x+4)+(x+7)+(x+10)+........+(x+28)=155
(X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
(X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
Tìm X : (X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
Tìm X: (X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
(x+1) + (x+4)+(x+7)+(x+10)+...+(x+28)=155
( x+1 ) + ( x+4 ) + ( x+7 ) + ( x+10 ) +...+ ( x+28 ) = 155
Tìm X :
(X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155.
Tìm X :
(X + 1) + (X + 4) + (X +7) +(X + 10) + . . . + (X + 28) = 155
