X+y and y+x are the same as stated by the commutative law.
This is because let’s say x=2 and y=3,
2+3=5 and 3+2=5
A- Stable electron configurations are likely to contain - filled energy sub-levels.
B- How many unpaired electrons are in a sulfur atom (atomic number 16)? Answer is 2
The answer would be ×>5 because when u divide by a negative the sign will switch.
Suppose

is the number of possible combinations for a suitcase with a lock consisting of

wheels. If you added one more wheel onto the lock, there would only be 9 allowed possible digits you can use for the new wheel. This means the number of possible combinations for

wheels, or

is given recursively by the formula

starting with

(because you can start the combination with any one of the ten available digits 0 through 9).
For example, if the combination for a 3-wheel lock is 282, then a 4-wheel lock can be any one of 2820, 2821, 2823, ..., 2829 (nine possibilities depending on the second-to-last digit).
By substitution, you have

This means a lock with 55 wheels will have

possible combinations (a number with 53 digits).
y=kx+b
for (7,-8): -8=7k+b. (function 1)
for (-4,6): 6=-4k+b (function 2)
Use function 2 - function 1
we get: 14=-11k
k=-14/11------>slope is -14/11
Now we know that first two options are wrong since they have the wrong slope for the function.
Plus -14/11 back to function 1/ or 2. Both are correct and can give you the answer. In this case I would plug it back to function 2.
6=14*4/11+b
b=66/11-56/11
b=10/11
We get y=-14/11x+10/11
subtract both side by 6.
y-6=-14/11x+10/11-66/11
y-6=-14/11x-56/11
y-6=-14/11(x+4)
So C is correct