- 25 - ( x + 5 ) = 415 + 5( x - 83 )
- 25 - x-5= 415+ 5x -415
- 30-x = 415 -415 +5x
-30-x = 5x
-30= x+ 5x
-30 = 6x
-30:6= x
-5 = x
Vậy...
-25 - ( x + 5 ) = 415 + 5( x - 83 )
-25 - x - 5 = 415 + 5x - 415
( -25 - 5 ) - x = ( 415 - 415 ) +5x
-30 - x = 5x
-30 = 5x + x
-30 = 6x
x = ( -30) :6
* = -5