Answer:
[tex]\frac{4^{21} }{5^{6}}[/tex]
Step-by-step explanation:
[tex](\frac{4^{7} }{5^{2}} )^{3}=\frac{4^{7\times3} }{5^{2\times3} } =\frac{4^{21}}{5^{6}}[/tex]
A
