On the system of equations 3x + YK + 1, x + 3Y = 3 of X, and X + y is nonnegative, what is the range of K?

On the system of equations 3x + YK + 1, x + 3Y = 3 of X, and X + y is nonnegative, what is the range of K?

From the equations, x = (3K + 3) / (K-9) y = 10 / (9-k)
x+y=(3k-7)/(k-9)>=0 k9