Answer:
To find the intersection point of the polynomial with the y-axis, substitute 0 for each x.
[tex]f(x)=-9x-5x^2+9x^3+7\\\\f(0)=-9\times0-5\times0^2+9\times 0^3+7\\\\f(0)=0-0+9+7\\\\\boxed{\bold{f(0)=7}}[/tex]
Therefore, the y-coordinate of the y-intercept of the polynomial function is 7.
