Question 1029917
Let {{{ n }}} = number of jerseys purchased
Let {{{ C }}} = the cost of buying {{{ n }}}
number of jerseys
---------------------
Jerseys Unlimited:
{{{ C = 40n + 80 }}}
Uniforms R Us:
{{{ C = 50n }}}
----------------
Make the costs equal
{{{ 40n + 80 = 50n }}}
{{{ 10n = 80 }}}
{{{ n = 8 }}}
------------
If they buy 8 jerseys, the costs are equal
If they buy 9 jerseys, Jerseys Unlimited 
is the better option
-------------------
check
Uniforms R Us:
{{{ C = 50n }}}
{{{ C = 50*9 }}}
{{{ C = 450 }}}
and
Jerseys Unlimited:
{{{ C = 40n + 80 }}}
{{{ C = 40*9 + 80 }}}
{{{ C = 360 + 80 }}}
{{{ C = 440 }}}
OK