Answer:
A. 5^20 x 7^40
Step-by-step explanation:
The exponent outside applies to each factor inside parentheses. The rules of exponents say ...
(a^b)^c = a^(b·c)
so, you have ...
[tex](5^2\times 7^4)^{10}=5^{2\cdot 10}\times 7^{4\cdot 10}=5^{20}\times 7^{40}[/tex]
