Problem #1:
$${\mathtt{2}}{\mathtt{\,\times\,}}\left({\mathtt{r}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2}}\right){\mathtt{\,\small\textbf+\,}}{\mathtt{5}}{\mathtt{\,\times\,}}\left({\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{r}}\right) = {\mathtt{63}}$$
2*r=2r
2*2=4
5*1=5
5*5r=25r
2r+4+5+25r=63
2r+25r=27r
4+5=9
$${\mathtt{27}}{\mathtt{\,\times\,}}{\mathtt{r}}{\mathtt{\,\small\textbf+\,}}{\mathtt{9}} = {\mathtt{63}}$$
$${\mathtt{63}}{\mathtt{\,-\,}}{\mathtt{9}} = {\mathtt{54}}$$
$${\mathtt{27}}{\mathtt{\,\times\,}}{\mathtt{r}} = {\mathtt{54}}$$
54/27 and 27/27= 2
$${\mathtt{R}} = {\mathtt{2}}$$
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