Tính

$$\begin{gathered} 1.\surd 3= \\ 2.\mathrm{\pi }+\mathrm{\pi }= \\ 3.100\mathrm{mph}=??? \mathrm{kmh} \\ 4.\frac{2 \mathrm{x} 4}{4 \mathrm{x} 2}+\frac{9 \mathrm{x} 6}{6 \mathrm{x} 9 }= \\ 5.\infty \mathrm{\pi }-\infty = \\ \mathrm{a}. \mathrm{\pi } \mathrm{b}.\infty \mathrm{c}.\infty \mathrm{\pi } \mathrm{d}.\mathrm{\pi }\infty \end{gathered}$$

trả lời nhanh thì tick cho