3x+y=-4

x=3-3y
y=2x
x+2y=-4

You have written four equations in two unknowns. There is no x,y combination that satisfies all of them. What is your question?

Based on the system of equations provided, it appears that there is no solution that satisfies all four equations simultaneously. This means that there is no unique combination of values for x and y that can satisfy all four equations at once.

To determine if a system of equations has a solution, you can solve the system using different methods such as substitution, elimination, or graphing.

In this particular case, let's use the method of substitution to analyze the equations. We'll start by solving one equation for either x or y and then substitute the solution into the other equations.

1) 3x + y = -4
2) x = 3 - 3y
3) y = 2x
4) x + 2y = -4

From equation 2), we can express x in terms of y:
x = 3 - 3y

Now let's substitute x = 3 - 3y into the other equations:

Substitute into equation 1):
3(3 - 3y) + y = -4
Simplifying:
9 - 9y + y = -4
-8y = -13
y = -13/-8
y = 13/8

Substitute y = 13/8 into equation 2):
x = 3 - 3(13/8)
x = 24/8 - 39/8
x = -15/8

Now let's substitute these values into the remaining equations:

Substitute y = 13/8 into equation 3):
13/4 = 2x
x = 13/8

Substitute x = -15/8 into equation 4):
-15/8 + 2(13/8) = -4
-15/8 + 26/8 = -4
11/8 ≠ -4

As we can see, when we substitute the values of x = -15/8 and y = 13/8 into the fourth equation, it does not hold true. Therefore, this set of equations has no common solution.

In conclusion, this system of equations is inconsistent, meaning there is no combination of x and y that satisfies all four equations simultaneously.