Question 280174
F=Fax paper cases
C=Copier paper cases
so {{{F+C=250}}}
so if 1F=$17 and 1C=$11
then $17 times F =cost of total fax paper cases and $11 times C = cost of total copier paper cases, so: 
{{{17F+11C=3650}}}
{{{F=250-C}}} substitute for {{{F}}} and solve for {{{C}}}
{{{17(250-C)+11C=3650}}}
{{{4250-17C+11C=3650}}}
{{{4250-6C=3650}}}
{{{-6C=-600}}}
{{{highlight(C=100)}}}
{{{F=250-C}}}
{{{F=250-100}}}
{{{F=150}}}