Theo đề ta có:
11- (15 + 11) = x - (25 - 9)
=> 11 - 15 -11 = x - 25 + 9
=> -15 = x - 16
=> x = -15 + 16
=> x = 1
11 - ( 15 + 11 ) = x - ( 25 - 9 )
11 - 26 = x - 16
- 15 = x - 16
x - 16 = -15
x = (-15) + 16
x = 1
11-(15+11)=x-(25-9)
11-26= x-16
-15= x-16
(-15)+16=x
-1
Vậy x = -1