Expanding (3y - 4)^2
The expression (3y - 4)^2 represents the square of a binomial. To expand it, we can use the FOIL method or the pattern for squaring a binomial.
Using FOIL
FOIL stands for First, Outer, Inner, Last, which helps us remember the order to multiply the terms:
- First: Multiply the first terms of each binomial: (3y)(3y) = 9y^2
- Outer: Multiply the outer terms: (3y)(-4) = -12y
- Inner: Multiply the inner terms: (-4)(3y) = -12y
- Last: Multiply the last terms: (-4)(-4) = 16
Now, combine the terms: 9y^2 - 12y - 12y + 16
Finally, simplify by combining like terms: 9y^2 - 24y + 16
Using the Pattern
Squaring a binomial follows a pattern: (a + b)^2 = a^2 + 2ab + b^2. We can apply this pattern to our expression:
- Square the first term: (3y)^2 = 9y^2
- Multiply the two terms and double the product: 2(3y)(-4) = -24y
- Square the second term: (-4)^2 = 16
Combine the terms: 9y^2 - 24y + 16
Conclusion
Both methods lead to the same expanded form of (3y - 4)^2: 9y^2 - 24y + 16. Choose the method you find easier or more comfortable to use.