Answer with Step-by-step explanation:
We are given that A,B,C,D,E and F.
We have to find the number of different four -letter arrangements can be formed using given six letters a,if the first letter must be C and one of the other letters must be B and no letter can be used more than once in the arrangement.
Number of letters=6
We have to arrange four letter out of six
After fixing C and B then we choose only two letters out of remaining four letters and repetition is not allowed.
Permutation formula :
We have n=4 an r=2
Using this formula and substitute the values
Then, we get 

Hence, number of different four -letter arrangements can be formed using six letters when repetition is not allowed=12
Answer:
x=7
Step-by-step explanation:
-6 + 4x = x + 15
3x = 21
x=7
Answer: 32
Step-by-step explanation:
4cm × 8cm = 32cm
Answer:
I don't really have an answer for you but if you need help to get your answer use an app called Cymath it can help with your problems i've used this app a lot of times for this kind of math :)
Step-by-step explanation:
Hope i helped!!