00:01
Okay, so we're going to be solving the system of equations 2x minus 5y equals 1, and 3x plus y equals negative 7.
00:19
We're going to be using the substitution method.
00:22
So the first thing we're going to do is to get one of our variables in terms of the other.
00:27
Now, in this second equation, this y here does not have a coefficient.
00:32
It has a coefficient of 1.
00:33
So it's going to be easy to get that y by itself there.
00:37
So i'm going to subtract 3x from both sides of this equation and get y equals negative 7 minus 3x.
00:51
And since y is equal to negative 7 minus 3x, i'm going to be able to substitute that into this first equation up here.
01:01
So 2x minus 5 times.
01:04
Times y, y is equal to negative 7 minus 3x, and that's equal to 1.
01:14
So now we're going to solve this equation here for x.
01:17
I'm going to distribute that minus 5 as a negative 5.
01:22
So that's going to be plus 35, and then that minus 5 times the minus 3x.
01:30
That's a negative times a negative...