W = L - 7in
Rectangular area = L × W
44 = (L)×( L - 7)
44 = L × L - 7L
44 = L^2 - 7L
L^2 - 7L - 44 = 0
Applying the Bhaskara
a = 1
b = -7
c = -44
Delta = b^2 -4.a.c
Delta = (-7)^2 - 4.1.(-44)
Delta = 49 + 176
Delta = 225
Then us stay with:
L = [ -b +/- √(Delta) ]/2a
L = [ -(-7) +/- √225 ]/2(1)
L = [ 7 +/- 15 ]/2
We have two possibilities
L' = (7-15)/2
L' = -4
But, L' = -4 it is false.
Because, there isn't mearures negative.
Then,
L'' = [ 7 + 15]/2
L" = 11 in
That's right now.
