Question 1112234
(a)
{{{ M/30 }}} = the number of matches in each box
(b)
{{{ M/30 - 3 }}} = number of matches/box with
three fewer per box
----------------------------
[ matches/box ] x [ number of boxes ] = [ total number of matches ]
{{{ ( M/30 - 3 )*32 = M }}}
{{{ M*( 32/30 ) - 3*32 = M }}}
Multiply both sides by {{{ 30 }}}
{{{ 32M - 96*30 = 30M }}}
{{{ 2M = 2880 }}}
{{{ M = 1440 }}}
-------------------------
check answer:
{{{ ( M/30 - 3 )*32 = M }}}
{{{ ( 1440/30 - 3 )*32 = 1440 |}}}
{{{ ( 48 - 3 )*32 = 1440 }}}
{{{ 45*32 = 1440 }}}
{{{ 1440 = 1440 }}}
OK