Answer:
B. -21a-15
Step-by-step Explanation:

Answer: A
Step-by-step explanation: A function means that your x can only have one y but your y can have multiple x's.
Answer:
2100
Step-by-step explanation:
In how many ways can a group of 10 people be divided into three groups consisting of 2,3, and 5 people?
First, you need to choose 4 people to fill the first group.
The number of ways is (104) which equals to 210.
Then, pick 3 more people out of the remaining 6 to be in the second group. And then, pick 3 more out of the remaining 3.
However, we need to divide it by 2, since we don’t really care on the order of selection of group.
(63)(33)/2=10
So, there are 210 x 10 = 2100 ways
<span>(143(5) + 67)5
Multiply 143 by 5
(715 + 67)5
Add the numbers inside the parenthesis(715 and 67).
(782)5
Multiply 782 by 5.
Final Answer: 3,910</span>