Tính

$$\begin{gathered} Bài 1: \\ a\left)\frac{20,2\times 5,1-30,3\times 3,14+14,58}{14,58\times 460+7,29\times 540\times 2} \\ b\right)\frac{8,1÷0,6\times 1875+1,5\times 625\times 9}{105+205+795+895} \\ c)\left(54321\times 16÷12345\right)\times \left(54321÷15\right) \end{gathered}$$$MÌNH CẦN GẤP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!$