Đơn giản biểu thức: a) 25 – x – 32 b) a – 12 + 8 – a c) a – b – 17 + 8 + b d) 16 – (x – 4)+ (x – 12+ b)

a) 25 – x – 32 =-7-x

b) a – 12 + 8 – a=-4

c) a – b – 17 + 8 + b=a-9

d) 16 – (x – 4)+ (x – 12+ b)=16 – x + 4+ x – 12+ b=8+b