3(x-4)-x+5=-17
3(x-4)-x=-17-5
3(x-4)-x=-22
suy ra de bai ban ra sai 22:3 ko duoc
x thuoc rong
<=> 3x - 3.4 - x + 5 = - 17
<=> 3x - 12 - x + 5 = - 17
<=> 3x + ( - 12 ) + ( - x ) + 5 = - 17
<=> [ 3x + ( - x ) ] + [ ( -12 ) + 5 ] = - 17
<=> 2x + ( - 7 ) = - 17
<=> 2x = - 17 + 7
<=> 2x = -10
=> x = - 10 : 2
=> x = - 5
Vậy x = - 5