a, 31
b,28 hoặc (-2)8
c,27 hoặc (-2)7
d,31
a)\(=9.\frac{3.3^2}{81}=3^2.\frac{81}{81}=3^2\)
c) \(=3^2.2^5.\frac{2^2}{3^2}=2^5.\frac{4.3^2}{9}=2^5.4=2^5.2^2=2^7\)
b) \(=2^2.2^5:\left(\frac{8}{16}\right)=2^7:\frac{1}{2}=\frac{2^7.2}{1}=2^8\)
d) \(=\frac{1^2}{3^2}\times\frac{1}{3}\times9^2=\frac{1}{9}\times\frac{1}{3}\times9^2=\frac{9^2}{27}=\frac{3^4}{3^3}=3^1\)