\(218-\left(x+31\right)=x-29\)
\(\Leftrightarrow\)\(218-x-31=x-29\)
\(\Leftrightarrow\)\(187-x=x-29\)
\(\Leftrightarrow\)\(2x=216\)
\(\Leftrightarrow\)\(x=108\)
Vậy....
218-(x + 31) = x - 29
=> 218 - x - 31 = x - 29
=> (218-31) - x = x - 29
=> 187 - x = x - 29
=> -x - x = -29 - 187
=> -2x = -216
=> x = -216 : (-2)
=> x = 108
218 - ( x + 31 ) = x - 29
x + 31 + x - 29 = 218
2x + 2 = 218
2x = 218 - 2
2x = 216
x = 216 : 2
x = 108
Theo bài ra, ta có:
218 - ( x + 31 ) = x - 29
=> 218 - x - 31 = x - 29
=> 187 - x = x - 29
=> x - ( 187 - x ) = 29
=> x - 187 + x = 29
=> 2x - 187 = 29
=> 2x = 29 + 187
=> 2x = 216
=> x = 108
218-(x + 31) = x - 29
=> 218 - x - 31 = x - 29
=> (218-31) - x = x - 29
=> 187 - x = x - 29
=> -x - x = -29 - 187
=> -2x = -216
=> x = -216 : (-2)
=> x = 108
Hok tốt !
218 - ( x + 31 ) = x - 29
=> 218 - x - 31 = x - 29
=> ( 218 - 31 ) - x = x - 29
=> 187 - x = x - 29
=> -x - x = - 29 - 187
=> - 2x = - 216
=> x = -216 : ( - 2 )
=> x = 108