Linear Equations Introduction - By tecmath
Transcript
00:0-1 | Good day . Welcome to the Tech Math channel . | |
00:01 | What we're gonna be having to look at in this | |
00:02 | video is linear equations . It's gonna be part of | |
00:05 | a series of videos . We're going to be having | |
00:07 | a look at linear equation . So this one is | |
00:08 | just a bit of an introduction . Uh , so | |
00:11 | what are linear equations ? Well , these put simply | |
00:13 | pretty much if you were to graph a linear equation | |
00:15 | , which will show you in a second , they | |
00:18 | come out straight law . And since they're called linear | |
00:19 | equations are their equations . That if you look at | |
00:22 | the relationships between the different parts of it , they | |
00:24 | go up by very regular amount . So that that's | |
00:27 | the reason for the straight line . So although it | |
00:29 | straight into what an example of a linear equation is | |
00:32 | quite commonly , you'll see one that will look like | |
00:35 | this . Why equals two X plus one . And | |
00:40 | if I was to graph this , okay , we | |
00:42 | have two variables here , we have the Y , | |
00:44 | and we have the X . And if I was | |
00:46 | to graph this it will come out as a straight | |
00:48 | line . In fact , I'll tell you what , | |
00:49 | I'll show you this right now . So say the | |
00:53 | easiest way to do this when we first do these | |
00:55 | is we're going to put in a make a bit | |
00:57 | of a table up for ex and why And we'll | |
01:02 | put in values of X and see what why comes | |
01:04 | out . And then we'll graph to see what happens | |
01:06 | . Okay ? So first off I'm going to start | |
01:08 | with -3 . They're not gonna go minus two for | |
01:11 | x minus 10123 Okay . And we'll work out what | |
01:17 | these are . So let's put that little grid in | |
01:19 | to help us are you know to see what we're | |
01:21 | doing and now we'll work out what the Y values | |
01:24 | are . So if y equals two X plus one | |
01:28 | or two times X two times minus three for minus | |
01:31 | three X value two times minus three is minus six | |
01:34 | plus one is Boris five . Okay If X equals | |
01:40 | minus two minus two times two is minus four plus | |
01:44 | one is minus three . If X equals minus one | |
01:47 | minus one times two is minus two plus one is | |
01:52 | minus one . And you're gonna see already we're going | |
01:54 | up by two so far each time . What do | |
01:58 | you think this one will be ? We'll have a | |
01:59 | look if X equals zero zero times 20 plus one | |
02:04 | is one . So we're going up by a regular | |
02:07 | amount each time . This is a pretty normal thing | |
02:09 | with linear equations . So we're going to go up | |
02:11 | by regular amounts . It's going to be very uh | |
02:14 | it's something which always happens . So the next one | |
02:17 | you can probably guess will be a three . This | |
02:18 | one here will be a five and that one there | |
02:21 | will be a seven and you can check those out | |
02:22 | . You can you can substitute the X . Values | |
02:25 | into the equation if you want to check that out | |
02:28 | . Okay so now I've zoomed out a bit and | |
02:30 | put an access up so we can grab this linear | |
02:32 | equation . We can you can see what they look | |
02:34 | like . They're gonna see I've got two axes here | |
02:36 | , this is an axis here , the vertical one | |
02:38 | which is the y axes . We're gonna put the | |
02:40 | Y values along here , that's where the y values | |
02:42 | go . And along here you have the horizontal x | |
02:46 | axes . Okay And so we're gonna put these values | |
02:50 | in here and you'll see why it's called a linear | |
02:52 | equation . So without much further ado we got where | |
02:55 | we have an ex of minus three , we have | |
02:57 | a wide of minus five x minus three . And | |
03:00 | Why is it -5 ? Where X equals -2 ? | |
03:05 | We have a wide of -3 , so -2 -3 | |
03:09 | . We have a modest one X . And a | |
03:11 | modest one way . So they're here , you're going | |
03:13 | to see straight away , we're going up , you | |
03:15 | know the norse Straight line . It started off where | |
03:20 | X is equal to zero . We have why being | |
03:23 | equal to one where X is equal to one ? | |
03:26 | We have y equal to three where X is equal | |
03:29 | to two . We have y equal to five and | |
03:31 | we're X is equal three . We have y equal | |
03:33 | to seven . So we have this nice straight line | |
03:37 | . I'm gonna draw freehand . We'll see how that | |
03:38 | goes . Not too bad . It could have been | |
03:41 | a straight a straight line . You can see this | |
03:42 | is a nice straight line that goes through , hence | |
03:45 | the thing linear equation . The other thing you're going | |
03:47 | to see is if I zoom in that these are | |
03:50 | going up by very regular amounts , Okay , you're | |
03:53 | going to see that for the amount that we go | |
03:56 | across one it's going up to , and we go | |
03:59 | across one and it's going up by two . And | |
04:02 | this is a fairly regular thing . This is this | |
04:05 | is something that happens with linear equations . Anyway . | |
04:10 | Uh just before the last thing , I want to | |
04:12 | tell you this , and we are going to do | |
04:14 | a whole bunch more things on linear equations will be | |
04:16 | . How do you recognize a linear equation without having | |
04:19 | to graph it up each time ? Well , it's | |
04:21 | fairly simple and I'll tell you right now how to | |
04:23 | do it . So how do we tell a linear | |
04:26 | equation just by looking at it ? Well , you | |
04:28 | can it's really simple . You're just looking for three | |
04:31 | key things . There's three conditions that we're trying to | |
04:34 | meet when we look at linear equations . And the | |
04:36 | first is this linear equations can have these things called | |
04:40 | constants . They don't have to have them . And | |
04:43 | other equations can also have them . What is a | |
04:45 | constant ? A constant is something like one here ? | |
04:47 | Okay , It's one , it's always going to be | |
04:49 | a one . It's not changing its constant . Yeah | |
04:52 | . Other equations can also have a plus one at | |
04:54 | the end of them and not be linear . So | |
04:56 | this isn't the only thing we look at , and | |
04:58 | also a linear equation doesn't have to have this , | |
05:00 | but it's allowed to have it . Okay , you | |
05:03 | could have Y equals two X . And that would | |
05:05 | also give us a linear equation . So , there's | |
05:09 | a second condition we're gonna be looking for is where | |
05:11 | we look at the constance and the variables . Okay | |
05:14 | , so we can have a variable here . We | |
05:15 | have two variables in this equation . We have why | |
05:18 | we have X . But these variables and they can | |
05:21 | be multiplied by a constant here . But the variables | |
05:25 | are not raised to any power , like squared or | |
05:29 | cubed or they're not being square rooted . I'll give | |
05:31 | you an example here . If I was to say | |
05:33 | this equation here , why equals X squared ? This | |
05:38 | would not give us a linear graph . This is | |
05:41 | not a linear equation or why equals square root of | |
05:45 | X plus one . Okay , As a constant , | |
05:49 | it's allowed to have that . But this square root | |
05:51 | thing , it means straight away that this is not | |
05:53 | a linear equation . So if you see anything like | |
05:56 | this , you know , straight away , these are | |
05:58 | not linear equations . But if you just have X | |
06:01 | . If you had something like Y equals three x | |
06:04 | minus two , you can say , okay , look | |
06:07 | , these are not being raised up to any powers | |
06:09 | . And there's just some constants here . This will | |
06:11 | be a linear equation . There's a third thing we | |
06:14 | can also look for . Okay , and that's that | |
06:16 | the variables are not being multiplied together . So , | |
06:19 | say you had something like uh X Times y equals | |
06:24 | 10 . This would not give us a linear graph | |
06:29 | . This is not a linear equation . Okay . | |
06:32 | Uh Okay . So , this will give us actually | |
06:34 | a rather cool looking graphic was to draw it that | |
06:37 | looks like this . Okay , It's not a straight | |
06:40 | line graph . All right . So , pretty much | |
06:43 | we're looking for those three conditions . They can have | |
06:46 | constants that the variables aren't being squared or square root | |
06:49 | or anything like that , and that the variables are | |
06:52 | multiplying together . And if you fulfil those conditions , | |
06:55 | you've got yourself a linear equation . In fact , | |
06:58 | every straight line can be , uh can be represented | |
07:02 | by this equation that you might have seen before . | |
07:04 | You might have seen it as why equals mx plus | |
07:08 | B . You might have seen as plus C . | |
07:11 | Depending on where you come from . This equation is | |
07:13 | going to be really useful . We're gonna be having | |
07:15 | a look at the future videos and it's really , | |
07:18 | really good . You can tell a lot of things | |
07:19 | about linear equations just by looking at this particular equation | |
07:24 | . Anyway , I hope this was a fine introduction | |
07:27 | for linear equations for you . I'm looking forward to | |
07:29 | going through these are really like linear equations . So | |
07:32 | we'll see you soon . Okay , bye . |
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Linear Equations Introduction is a free educational video by tecmath.
This page not only allows students and teachers view Linear Equations Introduction videos but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.