*) x - ( 17 - x ) = x + 3
<=>x - 17 + x = x+ 3
<=>x + x - x = 3 + 17
<=>x = 20
Vậy x = 20.
*) - ( x + 12 ) + 35 = - 47
<=> - x - 12 + 35 = - 47
<=> - x = - 47 + 12 - 35
<=> - x = -70
<=> x = 70
Vậy x = 70.
*) 15 - ( - x + 32 ) = -11
<=> 15 + x - 32 = -11
<=> x = -11 -15 + 32
<=> x = 6
Vậy x = 6.