Answer:
Step-by-step explanation:
= 9 - 7x
3 times 2 -7 x + 3
6 - 7 x + 3
This is the answer the x=3 and the y=2
6 blue pencils and 3 red pencils means 9 total pencils. So the probability of pulling out ONE blue pencil would be 6/9 or about 67 percent. TWO blue pencils would be HALF of that. So 6/9 * 1/2 which is 6/18 or 1/3 or about 33 percent.
This is a problem of Permutations. We have 3 cases depending on the number of B's. Since no more than three B's can be used we can use either one, two or three B's at a time.
Case 1: Five A's and One B
Total number of letters = 6
Total number of words possible = 
Case 2: Five A's and Two B's
Total number of letters = 7
Total number of words possible = 
Case 3: Five A's and Three B's
Total number of letters = 8
Total number of words possible = 
Total number of possible words will be the sum of all three cases.
Therefore, the total number of words that can be written using exactly five A's and no more than three B's (and no other letters) are 6 + 21 + 56 = 83