Question 6300
x/5=4/x+1

cross multiply or multiply by the LCM that is 5(x+1)
x (x+1)=5 X 4
x^2 +x =20
x^2 + x -20=0

x^2 + 5x -4x -20=0
x(x +5) -4(x+5)=0
(x+5)(x-4)=0
x=-5 , x=+4