Đề bài

Tính

a) ${\left( {\dfrac{{ - 2}}{3}} \right)^3}.{\left( {\dfrac{{ - 2}}{3}} \right)^2}$

b) ${(0,15)^7}:{(0,15)^5}$

c) ${\left( {\dfrac{3}{5}} \right)^{15}}:{\left( {\dfrac{{27}}{{125}}} \right)^5}$

d) ${\left( {\dfrac{1}{7}} \right)^4}.\dfrac{1}{7}{.49^3}$