Answer :

To solve the system of equations:

[tex]\[ \begin{cases} 2x + y = 4 \\ x + y = -2 \end{cases} \][/tex]

we can use the method of elimination or substitution. Here, we will use the method of elimination.

### Step-by-Step Solution

1. Write down the system of equations:

[tex]\[ \begin{cases} 2x + y = 4 \quad \text{(1)} \\ x + y = -2 \quad \text{(2)} \end{cases} \][/tex]

2. Subtract Equation (2) from Equation (1):

[tex]\[ (2x + y) - (x + y) = 4 - (-2) \][/tex]

Simplify the left-hand side and the right-hand side:

[tex]\[ 2x + y - x - y = 4 + 2 \][/tex]

[tex]\[ x = 6 \][/tex]

Thus, we have found [tex]\( x = 6 \)[/tex].

3. Substitute [tex]\( x = 6 \)[/tex] back into one of the original equations to find [tex]\( y \)[/tex]. We will use Equation (2):

[tex]\[ x + y = -2 \][/tex]

Substitute [tex]\( x = 6 \)[/tex] into the equation:

[tex]\[ 6 + y = -2 \][/tex]

Solve for [tex]\( y \)[/tex]:

[tex]\[ y = -2 - 6 \][/tex]

[tex]\[ y = -8 \][/tex]

4. Write the solution as an ordered pair:

The solution to the system of equations is:

[tex]\[ (x, y) = (6, -8) \][/tex]

### Verify the Solution

To ensure our solution is correct, we can substitute [tex]\( x = 6 \)[/tex] and [tex]\( y = -8 \)[/tex] back into the original equations.

- For Equation (1):

[tex]\[ 2x + y = 4 \][/tex]

Substitute [tex]\( x = 6 \)[/tex] and [tex]\( y = -8 \)[/tex]:

[tex]\[ 2(6) + (-8) = 4 \][/tex]

[tex]\[ 12 - 8 = 4 \][/tex]

[tex]\[ 4 = 4 \quad \text{(True)} \][/tex]

- For Equation (2):

[tex]\[ x + y = -2 \][/tex]

Substitute [tex]\( x = 6 \)[/tex] and [tex]\( y = -8 \)[/tex]:

[tex]\[ 6 + (-8) = -2 \][/tex]

[tex]\[ -2 = -2 \quad \text{(True)} \][/tex]

Both equations are satisfied with the solution [tex]\( (6, -8) \)[/tex]. Therefore, the solution is confirmed to be correct. The values are [tex]\( x = 6 \)[/tex] and [tex]\( y = -8 \)[/tex].