7 . (2 + x) - 6 . (x - 3) = 18
=> 7 . 2 + 7x - (6x - 6 . 3) = 18
=> 14 + 7x - (6x - 18) = 18
=> 14 + 7x - 6x + 18 = 18
=> (7x - 6x) + (14 + 18) = 18
=> x + 32 = 18
=> x = 18 - 32
=> x = -14
Vậy x = -14
Ta có:
7(2 + x) - 6(x - 3) = 18
7.2 + 7x - 6x - 6.3 = 18
14 + 7x - 6x - 18 = 18
14 + x - 18 = 18
14 + x = 36
x = 36 - 14
x = 22
Vậy x = 22 là giá trị cần tìm
7. (2 + x) - 6 ( x - 3) = 18
14 + 7x - 6x - 14 = 18
( 7x - 6x ) - ( 14 + 18 ) = 18
x - 32 = 18
x = -14
Vậy x = -14