The stationary point is where the derivative = 0 [ the graph is "stationary"....neither increasing or decreasing ]
So.....using rhe quotient rule numerator [ we needn't worry about the denominator ].........we have
(2x + 4) (x^2 + 4x + 3) - (x^2 + 4x)(2x + 4) = 0 factor and simplify
(2x + 4) [ 3 ] = 0
2x + 4 = 0
x = -2
And y = [ (-2)^2 + 4*(-2) ] / [ (-2)^2 + 4*(-2) + 3 ] = -4 / -1 = 4
So...the "stationary point " is ( -2. 4 )
Here's the graph : https://www.desmos.com/calculator/o8zzqeulqu