a,(2600+6400)-3 .x = 1200
=> 9000-3 .x= 1200
=> 3.x= 7800
=. x=2600
b, (6.x-72):2-84= 201
(6x-72):2=285
6x-72=570
6x=642
x=107
a) ( 2600 + 6400 ) - 3 . x = 1200
9000 - 3 . x = 1200
3 . x = 9000 - 1200
3 . x = 7800
x = 7800 : 3
x = 2600
trả lời
a,(2600+6400)-3 .x = 1200
=> 9000-3 .x= 1200
=> 3.x= 7800 =. x=2600
b, (6.x-72):2-84= 201
(6x-72):2=285
6x-72=570
6x=642
x=107