McDougal Littell Algebra 2, Chapter 3, 3.2, Section 3.2, Problem 39

We could use any of these numbers to start off.
We can either choose to solve for x or y it doesn't matter. I will start by solving for y in 6x + 9y =-3
The first step is to move 6x to the other side by subtracting it because we are trying to get y alone.
9y = -3 - 6x
Now divide by 9 because it is standing in the way of y:
y = -3/9 - (6x)/9
We can simplify these:
y = -1/3 - (2x)/3
Now plug in these numbers as Y on the other problem:

-4x - 6(-1/3 - (2x)/3) = 11
distribute the -6

-4x + 2 + 4x = 11
combine like terms:

-4x + 4x + 2 = 11
2 != 11
therefore there are no numbers that could satisfy this equation.