Question

simplify the following expression. (4z + 9) - (3z - 9)

Explanation:

Step1: Distribute the negative sign

$4z + 9 - 3z + 9$

Step2: Combine like terms for $z$

$4z - 3z = z$

Step3: Combine constant terms

$9 + 9 = 18$

Step4: Combine results

$z + 18$

Answer:

$z + 18$