а) $$(12 \frac{1}{12})^2$$; б) $$(-7 \frac{2}{7})^2$$; в) $$(7 \frac{3}{14})^2$$; г) $$(-13 \frac{3}{13})^2$$.

a)

${\left(12\frac{1}{12}\right)}^2={\left(\frac{145}{12}\right)}^2=\frac{21025}{144}=146\frac{1}{144}$

б)

${(-7\frac{2}{7})}^2={(-\frac{51}{7})}^2=\frac{2601}{49}=53\frac{4}{49}$

в)

${\left(7\frac{3}{14}\right)}^2={\left(\frac{101}{14}\right)}^2=\frac{10201}{196}=52\frac{9}{196}$

г)

${(-13\frac{3}{13})}^2={(-\frac{172}{13})}^2=\frac{29584}{169}=175\frac{9}{169}$

Ответ: a) $$146 \frac{1}{144}$$; б) $$53 \frac{4}{49}$$; в) $$52 \frac{9}{196}$$; г) $$175 \frac{9}{169}$$