Respuesta :
P=2(L+W)
L=-3+2W
P=18
18=2(L+W)
divde 2 both sides
9=L+W
sub -3+2W for L
9=-3+2W+W
9=-3+3W
add 3 both sides
12=3W
divide both sides by 3
4=W
sub back
L=-3+2W
L=-3+2(4)
L=-3+8
L=5
it is 5cm by 4cm
L=-3+2W
P=18
18=2(L+W)
divde 2 both sides
9=L+W
sub -3+2W for L
9=-3+2W+W
9=-3+3W
add 3 both sides
12=3W
divide both sides by 3
4=W
sub back
L=-3+2W
L=-3+2(4)
L=-3+8
L=5
it is 5cm by 4cm