Random Variables

Step 1: Expand the binomial using the binomial theorem.
The given equation is . By using the binomial expansion, we expand it as: This gives:
Step 2: Find the sum .
The coefficients correspond to the terms for in the expansion. To find , we need to evaluate the sum of the coefficients of the terms from to . By substituting into the expansion, we get: So:
Step 3: Subtract from both sides.
To find , subtract from both sides: We can calculate using the binomial expansion, where : Thus: Thus, the sum of the coefficients is: