00:01
Hello! so here we have our system.
00:01
Our first equation is negative 2x plus 3y is equal to negative 7, and then we're given what y equals.
00:09
We've told that y here is equal to 5x plus 15.
00:13
So we have y in terms of x.
00:14
We can take that value for y and then just put it right into the first equation.
00:18
So we get negative 2 times x plus 3 times y.
00:22
But what is y? y is 5x plus 15, and that's going to be equal to negative 7.
00:28
So now we only have one variable, namely x, so we can then solve for x.
00:32
So we have negative 2x, and then this 3 is going to distribute, so plus 3 times 5x, so it's going to be 15x, and then 3 times 15, that's 10, 20, 30, it's like 40, 45, so plus 45 is equal to negative 7...
