Understanding the Expansion of (2a - 3)^2
The expression (2a - 3)^2 represents the square of the binomial (2a - 3). To understand its expansion, we need to apply the concept of squaring a binomial.
The FOIL Method
The FOIL method is a handy acronym that helps us remember the steps involved in expanding a binomial squared:
- First: Multiply the first terms of each binomial.
- Outer: Multiply the outer terms of the binomials.
- Inner: Multiply the inner terms of the binomials.
- Last: Multiply the last terms of each binomial.
Applying FOIL to (2a - 3)^2
Let's apply the FOIL method to expand (2a - 3)^2:
- First: (2a) * (2a) = 4a^2
- Outer: (2a) * (-3) = -6a
- Inner: (-3) * (2a) = -6a
- Last: (-3) * (-3) = 9
Now, combine the terms:
4a^2 - 6a - 6a + 9
Finally, simplify by combining like terms:
4a^2 - 12a + 9
Conclusion
Therefore, the expansion of (2a - 3)^2 is 4a^2 - 12a + 9. This is a trinomial, which is a polynomial with three terms.
Understanding the FOIL method allows us to effectively expand and simplify expressions like this, making it easier to work with them in various mathematical contexts.