Answer:
from top to bottom = c, d, a, b
Step-by-step explanation:
Answer:
first one
Step-by-step explanation:
Given a group of
n object. We want to make a selection of
k objects out of the n object. This can be done in
C(n, k) many ways, where

,
where k!=1*2*3*...(k-1)*k
Thus, we can do the selection of 3 cd's out of 5, in C(5,3) many ways,
where

Answer: 10
Answer: Assuming the a2 is a with an exponent of 2 and a3 is a with an exponent of 3, the answer is 2a^6-2a^5
Step-by-step explanation: the number after the ^ means to the power of