$a)4^3=4\cdot 4\cdot 4$

  ${11}^3=11\cdot 11\cdot 11$  

$7^3=7\cdot 7\cdot 7$

$b){1,2}^2=1,2\cdot 1,2$

${2,3}^3=2,3\cdot 2,3\cdot 2,3$

${1,5}^3=1,5\cdot 1,5\cdot 1,5$

   ${4,7}^2=4,7\cdot 4,7$  

$c){\left(\frac{3}{4}\right)}^2=\left(\frac{3}{4}\right)\cdot \left(\frac{3}{4}\right)$

${\left(\frac{1}{7}\right)}^3=\left(\frac{1}{7}\right)\cdot \left(\frac{1}{7}\right)\cdot \left(\frac{1}{7}\right)$

$2{\left(\frac{1}{5}\right)}^2=2\left(\frac{1}{5}\right)\cdot 2\left(\frac{1}{5}\right)\cdot 2\left(\frac{1}{5}\right)$