Uploaded by MATHRoberg on 04.10.2010

Transcript:

Hi, I'm Kendall Roberg, and here's how we multiply binomials using the FOIL method.

Now, FOIL is an acronym for First, Outer, Inner, Last.

Here, we have two binomials, and what FOIL tells us to do is first multiply the first terms, x and 3x.

x times 3x is 3(x)^2.

Next, we need to multiply the outer terms.

That is, x and -7.

x times -7 is -7x.

Next, we need to multiply the inner terms.

That is the 2 and the 3x.

2 times 3x is 6x.

And lastly, we need to multiply the last terms.

That's the 2 and the -7.

2 times -7 is -14.

Now, we're not finished yet because -7x and 6x are like terms, which means we need to combine them.

When we combine those like terms, -7x and 6x, we're left with -x.

So our final product is going to be 3(x)^2 - x - 14.

And there we have it...that's how we use FOIL to multiply binomials.

Now, FOIL is an acronym for First, Outer, Inner, Last.

Here, we have two binomials, and what FOIL tells us to do is first multiply the first terms, x and 3x.

x times 3x is 3(x)^2.

Next, we need to multiply the outer terms.

That is, x and -7.

x times -7 is -7x.

Next, we need to multiply the inner terms.

That is the 2 and the 3x.

2 times 3x is 6x.

And lastly, we need to multiply the last terms.

That's the 2 and the -7.

2 times -7 is -14.

Now, we're not finished yet because -7x and 6x are like terms, which means we need to combine them.

When we combine those like terms, -7x and 6x, we're left with -x.

So our final product is going to be 3(x)^2 - x - 14.

And there we have it...that's how we use FOIL to multiply binomials.