Let [tex]l=length[/tex] be length and [tex]w=width[/tex]
[tex]w=2l-3[/tex]
To find the perimeter add all the sides of the rectangle
[tex]Perimeter=w+w+l+l[/tex]
Replacing [tex]w=2l-3[/tex]
[tex](2l-3)+(2l-3)+l+l=51[/tex]
[tex]6l-6=51 [/tex]
add to both sides 6
[tex]6l=51+6[/tex]
[tex]6l=57[/tex]
Divide both sides with 6
[tex]l=57/6 \\ l=9.5[/tex]
[tex]w=2l-3 \\ w=2(9.5)-3\\ w=19-3\\ w=16[/tex]
