The formula for the perimeter of a rectangle is 2(l+w)
The formula for the area of a rectangle is lw
First you need to solve for w and l
w+12=l
2(l+w)=44
2[(w+12)+w]=44 (since you know w+12=l, you can plug that into the l value of the second equation. Now you only have 1 variable to solve for, w, instead of 2)
2(2w+12)=44 (I combined like terms inside the parentheses)
4w+24=44 (I distributed 2 to everything inside the parentheses)
4w=20 (I subtracted 24 from both sides)
w=5 (divide both sides by 4)
Now that we know what w is, we can plug that into the first equation to solve for l
5+12=l
l=17
Now we solve for area
17x5=237.16
A=237.16 cm^2