Question 47164
<pre><tt>perimeter=2length+2width

2width=1length.

ok let's replace width with w and length with l.  It is also safe to replace perimeter with 36 as that is its value.

36=2l+2w
2w=l

so let's substitute l with 2w in the first problem.

36=2(2w)+2w   simplify
36=6w         divide by 6, both sides
6=w

back to second equation:
2w=l

2(6)=l
12=l

length=12
width=6.</tt></pre>