Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Let's start by discussing what binomials are. A binomial is a polynomial with exactly two terms, such as (2a + 3b). Can anyone give me another example?
How about (x + 5)?
Great! Now, when we multiply two binomials, we use the distributive property. Does anyone remember what that means?
Is it like multiplying each term of one by every term of the other?
Exactly! This process is sometimes called the FOIL method, which stands for First, Outside, Inside, Last. It helps us remember how to multiply!
So if I have (a + 2) and (3 + b), I would multiply a by 3 and then by b, right?
Yes! Let's summarize. Binomials are two-term polynomials, and to multiply them, we apply the distributive property or FOIL.
Now, let's multiply two specific binomials: (2a + 3b) and (3a + 4b). Can someone remind me the first step?
We first distribute 3a to both terms in (2a + 3b), right?
Exactly! So we have 3a × 2a and 3a × 3b. Can anyone calculate those?
That gives us 6a² + 9ab.
Perfect! Now what do we do next?
We need to distribute 4b to (2a + 3b) as well.
Correct! 4b × 2a gives us 8ab and 4b × 3b gives us 12b². What do we do with all these results?
Combine like terms!
Right. So we end up with 6a² + 9ab + 8ab + 12b², which simplifies to 6a² + 17ab + 12b².
I see how combining like terms helps simplify it!
Now that we understand how to multiply binomials, can anyone think of a real-world scenario where this might apply?
What about calculating area? Like, if we have a rectangle whose sides are binomials?
Precisely! The area of a rectangle with lengths defined by binomials requires multiplying those binomials together.
So if I had a rectangle with sides (x + 2) and (x + 3), I could find its area?
Exactly! You would calculate (x + 2)(x + 3) using the steps we discussed.
And then combine like terms at the end!
Great summary! So remember, binomial multiplication has real-world applications like area calculation.
To multiply binomials, don’t be shy, | Use FOIL to simplify, | First, Outside, Inside, Last is the way, | Combine your terms for a brighter day!
Imagine two neighbors, Alex and Bella, each planting double rows of flowers labeled with terms. When they make their flowerbeds, each plant type looks to reach the garden sun, just like terms in multiplication combine for the perfect view.
Use F for the first factor, O for outside, I for inside, and L for last!
FOIL: First, Outside, Inside, Last.
Term
FOIL Method
Click to flip
Term
Distributive Property
Click to flip
Term
Like Terms
Click to flip
A polynomial with exactly two terms.
A property that allows us to multiply a single term by terms inside parentheses.
Terms in an expression that have the same variable raised to the same power.
An algebraic expression consisting of one or more terms.
This section teaches the process of multiplying binomials using the distributive property.
The section explains how to multiply two binomials by using the distributive law. It covers the steps required, provides examples, and emphasizes the importance of combining like terms in the resulting polynomial.
In this section, we delve into the multiplication of binomials, a foundational operation in algebra. To multiply two binomials, such as (2a + 3b) and (3a + 4b), we apply the distributive law which states that we multiply each term in the first binomial by every term in the second binomial. The mathematical expression is set up as:
(3a + 4b) × (2a + 3b) = 3a × (2a + 3b) + 4b × (2a + 3b)
This results in:
= (3a × 2a) + (3a × 3b) + (4b × 2a) + (4b × 3b) = 6a² + 9ab + 8ba + 12b²
After identifying like terms (where ba = ab) and combining them, we conclude with:
= 6a² + 17ab + 12b²
The importance of this section lies in understanding how to systematically multiply polynomials of varying degrees and combine like terms, which reinforces key algebraic skills.