(Z+2) (9-Z)

To simplify the expression (Z+2) (9-Z), we can use the distributive property of multiplication over addition/subtraction, which states that for any numbers a, b, and c:

a (b + c) = a*b + a*c.

Applying this property to our expression, we have:

(Z+2) (9-Z) = (Z * 9) + (Z * -Z) + (2 * 9) + (2 * -Z).

Now, let's simplify each term:

(Z * 9) = 9Z
(Z * -Z) = -Z^2 (multiplying a number by itself gives us the square of that number)
(2 * 9) = 18
(2 * -Z) = -2Z

Putting it all together, we get:

(Z+2) (9-Z) = 9Z - Z^2 + 18 - 2Z.

So, the simplified expression is:

9Z - Z^2 + 18 - 2Z.