$\text{a)}{4}^7={\left(2^2\right)}^7=2^{14}$  

$8^5={\left(2^3\right)}^5=2^{15}$  

${32}^{10}={\left(2^5\right)}^{10}=2^{50}$  

 

$\text{b)}{27}^{11}={\left(3^3\right)}^{11}=3^{33}$  

${81}^8={\left(3^4\right)}^8=3^{32}$  

$9^{12}={\left(3^2\right)}^{12}=3^{24}$  

 

$\text{c)}{49}^2={\left(7^2\right)}^2=7^4$  

${125}^4={\left(5^3\right)}^4=5^{12}$  

${121}^7={\left({11}^2\right)}^7={11}^{14}$