(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.