Well, I know to find the mean you add all the numbers and divide it by how many numbers there were, so I'm guessing you just do that with the stem and leaf plot. I hoped this helped a bit
For this case we have the following polynomials:

Adding the polynomials we have:

Rewriting we have:

Therefore, the result of the sum is:

Answer:
the sum of the polynomials is:

option 2
3z+2z and 5z 9.1+4.5a-2.5a and 11.1a and y-6(3) and y-18
The first step of simplifying the expression would be summing up the "i"s. They are separate ("+i" and "+5i") but you can still sum them up though they are apart. This is thanks to the commutative property of addition which allows summing the terms of an expression with several additions in whatever order it is prefered. Commutative means that the terms can be interchangeable.