Question 562702
Hi, it looks like she was also given the information that the dimensions differ by 20, like the length is 20 more than the width.  So one dimension is w and the other is w+20 (knowing only the perimeter is not enough to determine the dimensions uniquely).  So the first line would look like,
w+(w+20)+w+(w+20)=380
Solve for w:
4w+40=380
4w=340   (subtract 40)
w=85   (divide by 4)
One dimension is w=85, and the other dimension is w+20=85+20=105.