Expanding (x + 2y + 4z)²
Expanding the square of a trinomial like (x + 2y + 4z)² requires understanding the concept of FOIL (First, Outer, Inner, Last) and applying it to multiple terms. Here's a step-by-step breakdown:
1. Understand the Structure
The expression (x + 2y + 4z)² is equivalent to multiplying the trinomial by itself:
(x + 2y + 4z)² = (x + 2y + 4z)(x + 2y + 4z)
2. Apply the FOIL Method
We'll apply FOIL to the terms, remembering to distribute each term in the first trinomial to every term in the second:
- First: x * x = x²
- Outer: x * 2y = 2xy
- Inner: x * 4z = 4xz
- Last: 2y * x = 2xy
- Outer: 2y * 2y = 4y²
- Inner: 2y * 4z = 8yz
- Last: 4z * x = 4xz
- Outer: 4z * 2y = 8yz
- Last: 4z * 4z = 16z²
3. Combine Like Terms
After applying FOIL, we have the following expression:
x² + 2xy + 4xz + 2xy + 4y² + 8yz + 4xz + 8yz + 16z²
Combining like terms, we get the final expanded form:
x² + 4xy + 8xz + 4y² + 16yz + 16z²
Summary
The expanded form of (x + 2y + 4z)² is x² + 4xy + 8xz + 4y² + 16yz + 16z². This process can be generalized to expanding the square of any trinomial. Remember to carefully apply the FOIL method and combine like terms to get the final expression.