Answer:
[tex]length = x[/tex]
[tex]width = 2x - 3[/tex]
[tex]perimeter = 2(x + (2x - 3))[/tex]
[tex]51 = 2(3x - 3)[/tex]
[tex]51 = 6(x - 1)[/tex]
[tex]x - 1 = 8.5[/tex]
[tex]x = 9.5cm[/tex]
[tex]length = 9.5[/tex]
[tex]width = 2x - 3 = 2(9.5) - 3 = 16cm[/tex]
