Expanding (x+5)(x+8)
This expression represents the product of two binomials: (x+5) and (x+8). We can expand it using the FOIL method:
First: Multiply the first terms of each binomial: x * x = x²
Outer: Multiply the outer terms of the binomials: x * 8 = 8x
Inner: Multiply the inner terms of the binomials: 5 * x = 5x
Last: Multiply the last terms of each binomial: 5 * 8 = 40
Now, we combine the terms: x² + 8x + 5x + 40
Finally, simplify by combining the like terms: x² + 13x + 40
Therefore, the expanded form of (x+5)(x+8) is x² + 13x + 40.
Understanding the FOIL Method
The FOIL method is a mnemonic device that helps us remember the steps involved in multiplying two binomials. It stands for:
- First
- Outer
- Inner
- Last
This method ensures that we multiply each term of the first binomial by each term of the second binomial.
Applications
Expanding binomials like (x+5)(x+8) has many applications in algebra and other branches of mathematics. For instance, it is used in:
- Solving quadratic equations
- Factoring polynomials
- Graphing quadratic functions
- Calculus
By understanding how to expand binomials, we can gain a deeper understanding of these concepts.