Math Problem Statement

Expand (2x-3)'2 using binomial theorem

Solution

To expand (2x3)2(2x - 3)^2 using the binomial theorem:

The binomial theorem states:

(a+b)n=k=0n(nk)ankbk(a + b)^n = \sum_{k=0}^n \binom{n}{k} a^{n-k} b^k

Here:

  • a=2xa = 2x
  • b=3b = -3
  • n=2n = 2

The expansion for (2x3)2(2x - 3)^2 is:

(2x3)2=(20)(2x)2(3)0+(21)(2x)1(3)1+(22)(2x)0(3)2(2x - 3)^2 = \binom{2}{0}(2x)^2(-3)^0 + \binom{2}{1}(2x)^1(-3)^1 + \binom{2}{2}(2x)^0(-3)^2

Step-by-step calculation:

  1. (20)(2x)2(3)0=1(2x)21=4x2\binom{2}{0}(2x)^2(-3)^0 = 1 \cdot (2x)^2 \cdot 1 = 4x^2
  2. (21)(2x)1(3)1=2(2x)(3)=12x\binom{2}{1}(2x)^1(-3)^1 = 2 \cdot (2x) \cdot (-3) = -12x
  3. (22)(2x)0(3)2=119=9\binom{2}{2}(2x)^0(-3)^2 = 1 \cdot 1 \cdot 9 = 9

Final result:

(2x3)2=4x212x+9(2x - 3)^2 = 4x^2 - 12x + 9

Let me know if you'd like further explanation!

Related Questions:

  1. How do you generalize the binomial theorem for higher powers?
  2. What are the properties of binomial coefficients (nk)\binom{n}{k}?
  3. How can the binomial theorem be applied to negative or fractional exponents?
  4. What is the geometric interpretation of (2x3)2(2x - 3)^2?
  5. How does this method differ from direct multiplication of (2x3)(2x3)(2x - 3)(2x - 3)?

Tip:

Always verify binomial expansions by multiplying the terms directly as a cross-check!

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Math Problem Analysis

Mathematical Concepts

Algebra
Binomial Expansion
Quadratic Expressions

Formulas

Binomial theorem: (a + b)^n = Σ (n choose k) * a^(n-k) * b^k

Theorems

Binomial Theorem

Suitable Grade Level

Grades 9-11