00:01
For this problem, we've got two different, two or three different functions that we're going to evaluate different numbers for.
00:17
The first one is f of x equals nine minus six x.
00:22
And the first thing i'm supposed to do is put in a negative one.
00:27
So anytime you have a number in parentheses like this, you know, you're substituting it in for x.
00:35
It's just going in for x.
00:37
So i would have nine minus six times negative one.
00:42
Following orders of operations, you do this multiplying first.
00:46
Negative six times negative one is plus six.
00:50
So that's nine plus six, which is 15.
00:54
Now i'm going to put in a positive one.
00:57
Six times one is six and nine minus six is three.
01:01
And here i'm going to have nine minus six times negative three plus x.
01:09
So first thing i'm going to do is use distributive property.
01:13
So negative six times negative three is plus 18.
01:17
And negative six times x is minus 6x.
01:21
And nine and 18 is 27 minus 6x.
01:28
Alright, i'm going to erase this and write down my g function.
01:31
Okay, here's g of x.
01:35
It's equal to x squared minus 4x.
01:38
The first thing i'm supposed to do is put a two in.
01:41
So it's two squared minus four times two.
01:45
Two squared is four and four times two is eight.
01:49
Four minus eight is negative four.
01:52
And then i think this next one is a plus b.
01:57
So i'm going to put an a plus b in.
01:59
Okay, when you square a binomial like this, it's not going to be a squared plus b squared.
02:11
There's a middle term.
02:13
A plus b, the quantity squared, means a plus b times a plus b.
02:20
So it is a squared and the last one is b squared...