Question 694167
(x+5)(x-5)=39
x^2-5x+5x-25=39
x^2-25=39
x^2-64=0
x^2-8x+8x-64=0
x(x-8)+8(x-8)=0
(x-8)(x+8)=0
x-8=0 or x+8=0
x=8 or x=-8
8+5=13, 8-5=3, -8+5=-3, -8-5=-13
You can't have negatives as a length or width.
So x=8
Length=8+5
Width=8-5
Length=13
Width=3