The perimeter of a rectangular concrete patio is 38 meters. The area is 90 square meters. What are the dimensions of the patio?

Answer 1

2 L + 2 w = 38
so
L + w = 19 and L = 19-w

w L = 90
w (19-w) = 90
w^2 -19 w + 90 = 0
(w-9)(w-10) = 0
9 by 10

Answer 2

I dont understand how you got the answer