Tìm x

$$\begin{gathered} Bài 1: \\ a) 1,2\times \left(\frac{2,4\times x-0,23}{x}-0,05\right)=1,44 \\ b)\left(2,0+2,1+2,2+...+7,7+7,8,+7,9+8,0\right)÷\frac{26,49-23}{25\times 49+26} \end{gathered}$$