[tex]\it a)\ \ \dfrac{4^{13}\cdot2^{-10}}{16^3}=\dfrac{2^{26}\cdot\dfrac{1}{2^{10}}}{2^{12}}=\dfrac{2^{26}}{2^{12}\cdot2^{10}}=\dfrac{2^{26}}{2^{22}}=2^{26-22}=2^4=16\\ \\ \\ b)\ \ \dfrac{49^{-2}\cdot7^{12}}{48\cdot7^4+7^4}=\dfrac{7^{-4}\cdot7^{12}}{7^4(48+1)}=\dfrac{7^{-4+12}}{7^4\cdot7^2}=\dfrac{7^8}{7^6}=7^{8-6}=7^2=49[/tex]
