Sorry but this question does not really make sense.
X=numerator
y=denominator
the sum of numerator and denominator=x+y
we suggest this system of equations:
y=x-3
(x+5) / (y+5)=5/6
we solve this system of equation by substitution method.
(x+5) / (x-3+5)=5/6
(x+5) / (x+2)=5/6
6(x+5)=5(x+2)
6x+30=5x+10
6x-5x=10-30
x=-20
y=x-3=-20-3=-23
Teh sum of the numerator an denominator=-20+(-23)=-43
Answer: -43
The formula for the slope is 



Hope this helps.
頑張って!
Cos(theta) = adjacent/hypotenuse
cos(theta) = 6/20
cos(theta) = 0.3
Use the inverse cos or cos^-1 on your calculator to get the angle
theta = 72.5
if the length is 8ft and the width is (7+x) then the area would be 56+8x, if x is unknown.