$\frac{42\times 36}{7\times 4}=\frac{6\times \not{7}\times 9\times \not{4}}{\not{7}\times \not{4}}=\frac{54}{1}=54$
$\frac{56\times 45}{8\times 5}=\frac{7\times \not{8}\times 9\times \not{5}}{\not{8}\times \not{5}}= \frac{63}{1}=63$
$\frac{42\times 36}{7\times 4}=\frac{6\times \not{7}\times 9\times \not{4}}{\not{7}\times \not{4}}=\frac{54}{1}=54$
$\frac{56\times 45}{8\times 5}=\frac{7\times \not{8}\times 9\times \not{5}}{\not{8}\times \not{5}}= \frac{63}{1}=63$