Respuesta :
[tex]\bf \stackrel{\textit{1st week}}{(2b+3)}+\stackrel{\textit{2nd week}}{2(2b+3)}+\stackrel{\textit{3rd week}}{2[2(2b+3)]}~~=~~\stackrel{\textit{now in the bank}}{477} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ (2b+3)+(4b+6)(8b+12)=477\implies 14b+21=477\implies 14b=56 \\\\\\ b=\cfrac{56}{14}\implies b=4 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \stackrel{\textit{1st week}}{2(4)+3}\implies 11[/tex]