Answer:
L = 80 , w=60
Explanation:
l= w+20
perimeter: l+w+l+w=280
Plug in the value of L in place of L
(w+20)+w+(w+20)+w=280
Combine Like terms
and then separate the variables and knowns by subracting 40 from both sides
4w+40=280
-40 -40
Divide by 4 from both sides so (W) would be alone
4w=240
÷4 ÷4
You solved half the question now
w = 60
Remember the L at the top
we now know the value of W
so
L=(60)+20
L=80
just to be sure
80+80+60+60=280
you are welcome