Why does this latex code not display correctly in text cells


When I copy this latex code to a text cell of MMA, the typesetting is not correct. There are many line breaks in the result:

\begin{array}{*{20}{l}} {-1 < x < 1}\ {\mathop{{ \left( {1+x} \right) }}\nolimits^{{m}}=1+mx+\frac{{m{ \left( {m-1} \right) }}}{{2!}}\mathop{{x}}\nolimits^{{2}}+ \cdots +\frac{{m{ \left( {m-1} \right) } \cdots { \left( {m-n+1} \right) }}}{{n!}}\mathop{{x}}\nolimits^{{n}}+ \cdots }\ {\sqrt{{1+x}}=1+\frac{{1}}{{2}}x-\frac{{1}}{{2 \cdot 4}}\mathop{{x}}\nolimits^{{2}}+\frac{{1 \cdot 3}}{{2 \cdot 4 \cdot 6}}\mathop{{x}}\nolimits^{{3}}-\frac{{1 \cdot 3 \cdot 5}}{{2 \cdot 4 \cdot 6 \cdot 8}}\mathop{{x}}\nolimits^{{4}}+ \cdots }\ {\frac{{1}}{{\sqrt{{1+x}}}}=1-\frac{{1}}{{2}}x+\frac{{1 \cdot 3}}{{2 \cdot 4}}\mathop{{x}}\nolimits^{{2}}-\frac{{1 \cdot 3 \cdot 5}}{{2 \cdot 4 \cdot 6}}\mathop{{x}}\nolimits^{{3}}+\frac{{1 \cdot 3 \cdot 5 \cdot 7}}{{2 \cdot 4 \cdot 6 \cdot 8}}\mathop{{x}}\nolimits^{{4}}- \cdots } \end{array} 

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