I'll treat these like they're two seperate problems because how you set it up they're not together. If it's one whole problem please tell me and I'll solve it that way. :-)
First one: 3x+9+8x + 12
Collect like terms and simplify
(3x+8x)+(9+12)
11x+21
Second one: 2x + 6+x² + 6x + 9
Collect like terms and simplify

8x+15+
Hope this helps you, have a BLESSED and wonderful day, as well as a safe one!
-Cutiepatutie ☺❀❤
Answer:
D
Step-by-step explanation:
Plug in every scenario, in see if it equal to each other.
D is the only one that is equal.
9514 1404 393
Answer:
2
Step-by-step explanation:
The second step of the solution shows division by 2 on the left. Consequently, it must also show division by 2 on the right.
2 goes in the green box
_____

Answer:
Order of Operations was aught at a younger age for those just grasping the idea of multiplication and division. Exposing PEMDAS at a young age would confuse them too much, hence the order of operation groups, addition/subtraction and multiplication/division. So for the second example problem, PEMDAS would be correct because it does involve you to use parentheses as well as exponents to solve for. Very easy to mix up between order of operations and PEMDAS, but just look at it as if Order of operations is a beginner level of PEMDAS.
Step-by-step explanation:
Answer:
f(6) = -14
Step-by-step explanation:
x = -6
f(x) = x^2/3 - 2
f(-6) = (-6)^2/3 -2 Replace x with the given number
= -36/3 - 2 Simplify -6 to the power of 2
= - 12 - 2 Divide -36 by 3
f(6) = - 14 Subtract -2 from -12