Answer:

Step-by-step explanation:
First we calculate the number of possible ways to select 2 cards an ace and a card of 10 points.
There are 4 ace in the deck
There are 16 cards of 10 points in the deck
To make this calculation we use the formula of combinations

Where n is the total number of letters and r are chosen from them
The number of ways to choose 1 As is:

The number of ways to choose a 10-point letter is:

Therefore, the number of ways to choose an Ace and a 10-point card is:

Now the number of ways to choose any 2 cards from a deck of 52 cards is:


Therefore, the probability of obtaining an "blackjack" is:





This question wants you to find a common denominator for the fractions.
This means finding the LCM, least common multiple, for 21 and 9.
This can be done by listing the multiples for each number until they meet at a common one.
9:
9
18
27
36
45
54
63
21:
21
42
63
This means the LCM of 21 and 9 is 63.
So the lowest possible common denominator is 63.
21 • 3 = 63
So you have to multiply the numerator of 2/21 by 3 as well.
2 • 3 = 6
2/21 = 6/63
Now do the same for 1/9.
9 • 7 = 63
Multiply the numerator, 1, by 7.
1 • 7 = 7
1/9 = 7/63
So in the first blanks, you would put 6/63 for what 2/21 is equal to and 7/63 for what 1/9 is equal to.
7/63 is greater than 6/63.
7/63 > 6/63
That means 1/9 > 2/21
So 2/21 < 1/9 is the answer to the last blank.
Hope this helps!
Answer:
13x^2 - 6x -11
Step-by-step explanation: