1747 + 13212 - ? = 1123

$17\frac{4}{7} + 13\frac{2}{12} - ? = 11\frac{2}{3}$

$\frac{123}{7} + \frac{158}{12} - ? = \frac{35}{3}$

=>  $? = \frac{123}{7} + \frac{158}{12} - \frac{35}{3}$

=> ? =  $\frac{1476 + 1106 - 980}{84}$

=> ? = 19.07