Question

已知2的a次方为3,2的b次方为6,2的c次方为12,那么2c—（a+b）等于?

Answer 1

2^c/2^b=12/6=2

2^(c-b)=2

c-b=1

2^c/2^a=12/3=4

2^(c-a)=4

c-a=2

2c-(a+b)=2c-a-b=(c-a)+(c-b)

=2+1

=3