a) 456 + (x - 357) = 1362
x - 357 = 1362 - 456
x - 357 = 906
x = 906 + 357
x = 1263
Vậy x = 1263
b) (x -2005) . 2006 = 0
x - 2005 = 0 : 2006
x - 2005 = 0
x = 0 + 2005
x = 2005
Vậy x = 2005
c) 2005 . ( x -2006 ) = 2005
x - 2006 = 2005 : 2005
x - 2006 = 1
x = 1 + 2006
x = 2007
Vậy x = 2007
d) (2345 -x ) - 183 = 2014
2345 - x = 2014 + 183
2345 - x = 2197
x = 2345 - 2197
x = 148
Vậy x = 148
e) 480 + 45 .4 = ( x + 125 ) : 5 + 260
480 + 180 = ( x + 125 ) : 5 + 260
660 = ( x + 125 ) : 5 + 260
=> ( x + 125 ) : 5 + 260 = 660
( x + 125 ) : 5 = 660 - 260
( x + 125 ) : 5 = 400
x + 125 = 400 . 5
x + 125 = 2000
x = 2000 - 125
x = 1875
Vậy x = 1875
