00:01
Hi there, so for this problem we have the following two equations, 3 times x plus 9 times y, then this equals to 4, and the other one that we have is x plus 3 times y equals to minus 2.
00:21
We have this system of equations, so we need to find the values of y and the values of x that satisfy this equation.
00:33
So what we can do is to take the first equation, 3 times x plus 9 times y equals to 4.
00:42
And, well, there is a very easy way to do this.
00:46
You can identify that we have a 3 in here and that we have x in here.
00:51
So what we can do is to multiply all of the second expression by minus 3 and then add these two together.
01:00
So, for example, if we multiply it, well, that, well, let me just put it that in this way.
01:06
So we will have now, well, the one on top of this remains the same...