Expanding the Square: (-6x - 7y^2)^2
Squaring a binomial like (-6x - 7y^2)^2 involves using the FOIL method or recognizing the pattern of (a + b)^2. Let's break down both approaches:
Using the FOIL Method:
FOIL stands for First, Outer, Inner, Last and helps us multiply two binomials.
- First: Multiply the first terms of each binomial: (-6x) * (-6x) = 36x^2
- Outer: Multiply the outer terms: (-6x) * (-7y^2) = 42xy^2
- Inner: Multiply the inner terms: (-7y^2) * (-6x) = 42xy^2
- Last: Multiply the last terms: (-7y^2) * (-7y^2) = 49y^4
Finally, combine the terms:
36x^2 + 42xy^2 + 42xy^2 + 49y^4 = 36x^2 + 84xy^2 + 49y^4
Recognizing the Pattern:
The expression (a + b)^2 expands to a^2 + 2ab + b^2. We can apply this to our problem:
- a = -6x
- b = -7y^2
Substituting:
(-6x)^2 + 2(-6x)(-7y^2) + (-7y^2)^2 = 36x^2 + 84xy^2 + 49y^4
Conclusion
Both methods lead to the same answer: 36x^2 + 84xy^2 + 49y^4. Understanding both the FOIL method and the pattern for squaring binomials allows you to expand these expressions efficiently.