See attached picture for steps and answer:
Answer: a) 1977060966, b) 146581344.
Step-by-step explanation:
Since we have given that
There are 10 numbers,
There are 26 lower case letters,
There are 26 upper case letters,
Since the first 3 characters have to be digits and next 6 can be upper or lower.
So, a) repetitions are allowed:

b) repetitions are not allowed:

Hence, a) 1977060966, b) 146581344.
Answer:
x° = 67°
Step-by-step explanation:
1. The first three diagrams are showing you that opposite exterior angles are congruent. Based on that, when you are faced with opposite exterior angles in the fourth diagram, you are able to conclude they are congruent. That means x° = 67°.
2. You can determine the other angles in the figure based on linear angles being supplementary, and same-side interior angles being supplementary. After you work through all the angles, you find that x = 67.
Answer:
Solving the equation
we get 
Step-by-step explanation:
Noah's step to solve the equation
are:

The next step is to take square root on both sides because: 

Now, we know that: 

So, Solving the equation
we get 
Number seven it adds 30 each time it base a zero because u stars counting by zer