00:01
First thing we're asked to do is to write this matrix equation as a system of equations.
00:06
The idea would simply be this first column is representing the x's, whereas the second column is representing the y's.
00:15
Simply because we know if we are multiplying matrices, we take a row times a column, which means the two would go to the x and the three would go to the y.
00:25
So that's why it ends up working out that way.
00:28
Meaning we have equations of 2x plus 3y equals 5 and our second equation would be 4x plus 6y is equal to 9 that's the idea here now that we've got our equations set up our system of equations set up it's kind of up to you what method you want to use you could use graphing you could use substitution or you could use elimination i'm going to use elimination just because that tends to be the favorite of my students in class, so i figure it might be with you guys as well.
01:14
But if you prefer substitution or graphing, that's completely fine as well.
01:18
Truly whatever works best for you is fine, we should just have the same answer at the end, right? so if i want to use elimination, remember the whole goal is i want to cancel out either x or y.
01:29
Doesn't matter which one, it's up to me.
01:32
I guess i will try and cancel out the x's.
01:34
So i notice that if i take 2 times negative 2, that would give me a negative 4, which would cancel out with the positive 4x right here...