11. a) Se aplica formulele a^m*a^n=a^(m+n) si a^m:a^n=a^(m-n)
Raspunsul este (2/11)^10:(2/11)^3:(2/11)^5=(2/11)^7:(2/11)^5=(2/11)^2
sau mai rapid (2/11)^(6+4-3-5)=(2/11)^2
12. a) (1/2)^(6-3)+(1/2)^3=(1/2)^3+(1/2)^3=2*(1/2)^3=2*1^3/2^3=2*1/8=1/4
b) (1/3)^0=1
= 1-1/3-1/9-1/27=27/27-9/27-3/27-1/27=(27-9-3-1)/27=14/27
c) = (2/6+3/6)^2:5/12=(5/6)^2*12/5=5^2/6^2*12/5=25/36*12/5=5/3
d)= (3/3+1/3)^2:(3/3-1/3)^2=(4/3)^2:(2/3)^2=4^2/3^2: 2^2/3^2=16/9*9/4=4
