Question 1123766
let's the length be {{{L}}} and width {{{W}}}

if the width of a rectangle is three more than half the length, we have

 {{{W=L/2+3}}}....eq.1


if the perimeter is {{{78}}} centimeters, we have

{{{2(L+W)=78}}}....eq.2

substitute {{{W}}} from eq.1

{{{2(L+L/2+3)=78}}}...... solve for {{{L}}}

{{{2L+2(L/2)+2*3=78}}}

{{{2L+L+6=78}}}

{{{3L=78-6}}}

{{{L=72/3}}}

{{{highlight(L=24)}}}



go back to eq.1, substitute {{{L}}} and solve for {{{W}}}


 {{{W=24/2+3}}}....eq.1

{{{highlight(W=15)}}}



so, the length is {{{24}}} and width {{{15}}} centimeters