What is the coefficient of x^1 in the expansion of (x - 1)^5?

Practice Questions

Q1
What is the coefficient of x^1 in the expansion of (x - 1)^5?
  1. -5
  2. 5
  3. 10
  4. 15

Questions & Step-by-Step Solutions

What is the coefficient of x^1 in the expansion of (x - 1)^5?
  • Step 1: Identify the expression we are working with, which is (x - 1)^5.
  • Step 2: Understand that we want to find the coefficient of x^1 in the expansion of this expression.
  • Step 3: Use the Binomial Theorem, which states that (a + b)^n = Σ (nCk * a^(n-k) * b^k) for k = 0 to n.
  • Step 4: In our case, a = x, b = -1, and n = 5.
  • Step 5: We need to find the term where the power of x is 1, which means we want k = 4 (since 5 - k = 1).
  • Step 6: Calculate the binomial coefficient for k = 4, which is 5C4. This is equal to 5.
  • Step 7: Calculate (-1)^4, which is 1.
  • Step 8: Multiply the results from Step 6 and Step 7: 5 * 1 = 5.
  • Step 9: Conclude that the coefficient of x^1 in the expansion of (x - 1)^5 is 5.
No concepts available.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely