To evaluate the expression $y^2 + 9y - 5$ when $y = 2$, we can substitute $y = 2$ into the expression and simplify.

1. Start with the expression: $y^2 + 9y - 5$

2. Substitute $y = 2$: $(2)^2 + 9 \cdot (2) - 5$

3. Calculate each term:

   • $(2)^2 = 4$
   • $9 \cdot 2 = 18$
   • Then combine terms: $4 + 18 - 5$

4. Perform the addition and subtraction: $4 + 18 = 22$ $22 - 5 = 17$

So, the value of the expression when $y = 2$ is 17.

Would you like further explanation, or do you have any questions?

Here are some related questions for practice:

1. What is the result if $y = 3$ in the same expression $y^2 + 9y - 5$?
2. How would the expression change if it was $y^2 - 9y + 5$ instead?
3. Can you calculate $y^2 + 9y - 5$ if $y = -2$?
4. What is the impact on the expression $y^2 + 9y - 5$ if you increase $y$ by 1?
5. How can this expression $y^2 + 9y - 5$ be factored, if possible?

Tip: When evaluating expressions, always substitute carefully and handle each operation step-by-step to avoid mistakes.