Project Math Access DVD 03 - Algebra - Part 03
Transcript Start
Audio Description: Part three; solving equations using the FOIL method; example one.
TEACHER: Okay John, you want to look at the first problem and read what it is.
JOHN: Okay, in opening parenthesis we have 5X + 7 followed by a closing parenthesis. And the there's another opening parenthesis 3x+2, close parenthesis.
TEACHER: Okay, so what's the first thing we're going to do to solve it?
JOHN: This is the FOIL method, so we need to do the first numbers first. So 5x and 3x, I need to multiply those and becomes 15x.
TEACHER: It becomes....
JOHN: 15 x squared, rather.
Audio Description: John searches for the correct Tack Tiles.
JOHN: Okay, that's 1... that's my 5... is right down here. Okay, there we go.
Audio Description: John begins placing Tack Tiles in the upper left-hand corner.
JOHN: X...
TEACHER: It's on the other board.
JOHN: It's on the other board? Okay.
JOHN: X is right there. That's a fraction sign. X... is right there. Okay, 15x... Now what I need is a subscript.
Audio Description: He should have said he needed a "superscript."
JOHN: Okay- And then I'm going to use a number 2, which is right over here.
Alright, that's the first step. Now, we have to multiply the outside numbers. In this case the outside numbers are 5x and 2. So that would be 10x. So we need a "plus" sign That's right here.
Audio Description: John continues building the equation in the first line.
JOHN: I need to find my zero right away.
TEACHER: Go to the right, it's with the 9's in the same row.
JOHN: Okay. Here we go.
Audio Description: The teacher shows John where the nine is.
JOHN: And the zero is right here. And now we've got 10... And I need another X. Which is right up here. I'll go over to the right where I found the last one. Here we go. okay- Now we have that done... we have first and outsides done we go to the inside numbers. which are 7 and 3x. 7 times 3x is 21x. So we're going to add that on.
Audio Description: John continues building the equation on the first line with the Tack Tiles.
JOHN: 21... X's are up here. okay-
TEACHER: One more thing...
JOHN: One more thing... We have to do last numbers now. which are 7 and 2. So 7 mulitplied by 2 equals 14. And we need to add the 14.
Audio Description: John locates a plus sign and adds it to the equation.
JOHN: 1,... and the 4 are right here....
TEACHER: They're right under the 2's.
JOHN: Yeah, I got em.
TEACHER: Under the 2's.
JOHN: Here we go.
TEACHER: So, are we done?
JOHN: We are done.
TEACHER: With the whole problem?
JOHN: Now, what I'm going to do is look through the problem and see if there are any terms I can combine.
TEACHER: Good job.
JOHN: So, the line reads now... what we've done is put all of the first line... it's 15x squared plus 10x plus 21x... plus 14. Okay, the first thing that I see is that the 10x and 21x...
TEACHER: Let's start first with the x squared. Because we always want to start with the highest exponents.
JOHN: True. So I'm going to bring the 15x squared down to the next line.
TEACHER: Okay. Is there anything else you can combine the 15x squared with?
JOHN: No, considering it's the only squared... I'm trying to get some of these things off. They're pretty subborn. Fifteen... x...
Audio Description: John moves the Tack Tiles representing 15x squared, down to the next line.
JOHN: Squared... Here we go.
Okay- I'm also going to take the "plus" sign from up here. Here's where it gets different, though, because now I need 31, instead of... I'm in the wrong place there. Plus 31...
Audio Description: John searches for a Tack Tile three.
JOHN: Three's are right there.
TEACHER: No, three's are under the 1.
JOHN: Three's are under the 1, okay.
31... x... I'm just going to take the X from up here.
TEACHER: Now you should get rid of...
JOHN: And I'm going to get rid of these two numbers, as well.
Because...
TEACHER: Why are you getting rid of them?
JOHN: No, that's the 10, we don't need to get rid of those, but we do need to get rid of...
TEACHER: No, you're fine. What did you already do with the 10x and 21x?
JOHN: Okay, I should get rid of these then because we added them up already on the second line.
TEACHER: Right. So take them off so you'll know that you used them. So just take them off then.
JOHN: Okay.
TEACHER: So take them off the board, so you'll know you used them.
JOHN: 21... And, so all this stuff is used. Okay... and then, plus 14 we already said that there's nothing the 14 could combine with so I'm just going to take it down to the second line.
TEACHER: Good.
JOHN: So, let's see here...
JOHN: Plus 14... Oops. PIus14. Okay, so our final equation then reads... It reads 15x... squared pIus... 31x
JOHN: plus 14. TEACHER: Good job!