Question 759023


{{{One-fifth}}} the perimeter of a building is {{{50ft}}}.

{{{P=2(L+W)}}}....eq.1......the perimeter of a building 

{{{One-fifth}}} of the perimeter is {{{P/5=50ft}}}; so, the perimeter of a building is {{{P=50ft*5}}} => {{{P=250ft}}}

then
{{{250ft=2(L+W)}}}

{{{250ft/2=(L+W)}}}

{{{125ft=(L+W)}}}...solve for {{{L}}}

{{{L=125ft-W}}}......eq. 1a

if the length of the building {{{L}}} is {{{30ft}}} longer than the width {{{W}}}, than

{{{L=W+30ft}}}.......plug in eq.1a

{{{W+30ft=125ft-W}}}......eq. 1a....solve for {{{W}}}

{{{W+W=125ft-30ft}}}

{{{2W=95ft}}}

{{{W=95ft/2}}}

{{{highlight(W=47.5ft)}}}

now find {{{L}}}

{{{L=47.5ft+30ft}}}

{{{highlight(L=77.5ft)}}}

 the area of the building is {{{A=L*W}}}

{{{A=77.5ft*47.5ft}}}

{{{highlight(A=3681.25ft^2)}}}