00:01
Okay, so our first equation was x minus 2y plus 3 z is equal to 5.
00:05
So if we're going to multiply that first equation by negative 2, we're taking negative 2 times the first equation.
00:13
So if it's negative 2 times everything on the left -hand side and the right -hand side.
00:17
So multiplying everything by the last scalar, in this case, negative 2.
00:21
So what we get here is, well, we just distribute the negative 2.
00:24
So we get negative 2x, and then we get it plus 4y, and then we get it plus 4y, and then we're, minus 6 z is equal to negative 2 times 5 so it's equal to negative 10 okay then we're taking this we have here and we're adding it to equation 3 so equation 3 is 2x minus 3 z i'm just like the line up my terms right um is equal to well zero okay now if you want here you could put even a plus 0y, if that helps you, right, because there are no y terms, and then we're adding these equations together.
01:04
So we're just adding straight down.
01:06
Negative 2x plus 2x, well, that's 0x.
01:09
So if the xs are gone, and then we have 4y, well, plus 0y, so that's 4y...