i need help finding the excluded value(s) for this fraction?

Question

y^2-y+5/y+4

Answer 1

Assuming what you wrote is what you meant The equation is invalid when y=0, since the equation will go to +inf.

However if you meant (y^2-y+5)/(y+4) then:
The equation would be invalid at y = -4 for the same reason

Answer 2

y^2-y+5/y+4 is undefined when y=0

(y^2-y+5)/(y+4) is undefined when
y+4=0, i.e. y = -4

Answer 3

I assume you mean (y^2-y+5) / (y+4), and you want to know where it's undefined?

It's undefined at y=-4, because that is where a division by zero would occur.