Answer :

Certainly! Let's solve the problem step by step.

Given:

1. \( r = \binom{3}{1} \)
2. \( s = \binom{-2}{1} \)
3. We need to calculate \( 6(x + 2s) \)

### Step 1: Calculate \( r \)

The binomial coefficient \( \binom{3}{1} \) represents the number of ways to choose 1 element from a set of 3 elements. This can be calculated using the formula for binomial coefficients \( \binom{n}{k} = \frac{n!}{k!(n-k)!} \).

[tex]\[ \binom{3}{1} = \frac{3!}{1!(3-1)!} = \frac{3!}{1! \cdot 2!} = \frac{3 \times 2 \times 1}{1 \times (2 \times 1)} = 3 \][/tex]

So,

[tex]\[ r = 3 \][/tex]

### Step 2: Calculate \( s \)

The binomial coefficient \( \binom{-2}{1} \) usually isn't defined in the classical combinatorial sense because it involves a negative number. However, in the context of combinatorial interpretation with negative values, there is a convention that can be used.

For \( \binom{-n}{k} \), it is often defined as:

[tex]\[ \binom{-n}{k} = (-1)^k \binom{n+k-1}{k} \][/tex]

In this case, for \( n = 2 \) and \( k = 1 \):

[tex]\[ \binom{-2}{1} = (-1)^1 \binom{2 + 1 - 1}{1} = - \binom{2}{1} \][/tex]

Now calculating \( \binom{2}{1} \):

[tex]\[ \binom{2}{1} = \frac{2!}{1!(2-1)!} = \frac{2!}{1! \cdot 1!} = \frac{2}{1} = 2 \][/tex]

So,

[tex]\[ \binom{-2}{1} = -2 \][/tex]

Therefore,

[tex]\[ s = -2 \][/tex]

### Step 3: Calculate \( 6(x + 2s) \)

We need to evaluate the expression \( 6(x + 2s) \).

Substitute \( s = -2 \):

[tex]\[ 6(x + 2s) = 6(x + 2(-2)) = 6(x - 4) \][/tex]

### Step 4: Write the final expression

The answer in terms of \( x \) is:

[tex]\[ 6(x - 4) \][/tex]