Squaring a Binomial: (3x - 7y)²
In algebra, squaring a binomial is a common operation that involves multiplying a binomial by itself. This article will explore how to expand the expression (3x - 7y)².
Understanding the Concept
The expression (3x - 7y)² represents the product of (3x - 7y) multiplied by itself:
(3x - 7y)² = (3x - 7y) * (3x - 7y)
Expanding the Expression
To expand this expression, we can use the FOIL method, which stands for First, Outer, Inner, Last.
- First: Multiply the first terms of each binomial: (3x) * (3x) = 9x²
- Outer: Multiply the outer terms of each binomial: (3x) * (-7y) = -21xy
- Inner: Multiply the inner terms of each binomial: (-7y) * (3x) = -21xy
- Last: Multiply the last terms of each binomial: (-7y) * (-7y) = 49y²
Now, combine the results:
9x² - 21xy - 21xy + 49y²
Finally, simplify by combining like terms:
9x² - 42xy + 49y²
Conclusion
Therefore, the expanded form of (3x - 7y)² is 9x² - 42xy + 49y². This process demonstrates how to square a binomial by applying the FOIL method and simplifying the resulting expression.