Question 45010
37 cent stamps: b
20 cent stamps: s
{{{s + b = 20}}}
+
{{{.2s + .37b = 7.06}}}
so ....
{{{-.2s - .2b = -4}}}
+
{{{.2s + .37b = 7.06}}}
=
{{{.17b = 3.06}}}
{{{b = 18}}}
(b)