Question 954600
P=2(L+W)
54cm=2(L+W)
27cm=L+W
27cm-W=L
A=L*W
{{{140cm^2=L*W}}} Substitute for L.
{{{140cm^2=(27cm-W)W}}}
{{{140cm^2=27Wcm-W^2}}}
{{{W^2-27W+140=0}}}*[invoke quadratic "W", 1, -27, 140 ]
W=7cm 
ANSWER:The width is 7cm.
L=27cm-W=20 cm ANSWER 2: The length is 20 cm.
CHECK:
A=L*W
{{{140cm^2=20cm*7cm}}}
{{{140cm^2=140cm^2}}}
.
P=2(L+W)
54cm=2(20cm+7cm)
54cm=2(27cm)
54cm=54cm