Question 405238


A square plywood platform has a {{{perimeter}}} which is {{{7}}} times the length of a side {{{a}}},decreased by {{{18}}}.

{{{perimeter=P}}}


{{{P=4a}}}


{{{4a=7a-18}}}


{{{18=7a-4a}}}

{{{18=3a}}}

{{{18/3=a}}}

{{{a=6}}}