Identify the correct graph of the system of equations.

[tex]\[
\begin{array}{l}
3x - y = 12 \\
x + 4y = 4
\end{array}
\][/tex]



Answer :

To identify the correct graph of the system of equations given by:

[tex]\[ \begin{cases} 3x - y = 12 \\ x + 4y = 4 \end{cases} \][/tex]

we need to find the point of intersection of the two lines represented by these equations. This intersection point will be the solution to the system.

### Step-by-Step Solution:

1. Solve the system of equations:

[tex]\[ 3x - y = 12 \tag{1} \][/tex]

[tex]\[ x + 4y = 4 \tag{2} \][/tex]

We will solve these equations simultaneously.

2. From Equation (2), express [tex]\( x \)[/tex] in terms of [tex]\( y \)[/tex]:

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

3. Substitute [tex]\( x = 4 - 4y \)[/tex] into Equation (1):

[tex]\[ 3(4 - 4y) - y = 12 \][/tex]

Simplify:

[tex]\[ 12 - 12y - y = 12 \][/tex]

[tex]\[ 12 - 13y = 12 \][/tex]

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

[tex]\[ -13y = 0 \][/tex]

[tex]\[ y = 0 \][/tex]

4. Substitute [tex]\( y = 0 \)[/tex] back into [tex]\( x = 4 - 4y \)[/tex]:

[tex]\[ x = 4 - 4(0) \][/tex]

[tex]\[ x = 4 \][/tex]

The solution to the system of equations is [tex]\( x = 4 \)[/tex] and [tex]\( y = 0 \)[/tex]. So, the point of intersection of the two lines is [tex]\( (4, 0) \)[/tex].

5. Graph both equations on the coordinate plane:

- For the first equation [tex]\( 3x - y = 12 \)[/tex]:

- If [tex]\( x = 0 \)[/tex]:
[tex]\[ -y = 12 \implies y = -12 \quad \text{(Point: (0, -12))} \][/tex]

- If [tex]\( y = 0 \)[/tex]:
[tex]\[ 3x = 12 \implies x = 4 \quad \text{(Point: (4, 0))} \][/tex]

- For the second equation [tex]\( x + 4y = 4 \)[/tex]:

- If [tex]\( x = 0 \)[/tex]:
[tex]\[ 4y = 4 \implies y = 1 \quad \text{(Point: (0, 1))} \][/tex]

- If [tex]\( y = 0 \)[/tex]:
[tex]\[ x = 4 \quad \text{(Point: (4, 0))} \][/tex]

When you plot these points and draw the lines, you will find that they intersect at the point [tex]\( (4, 0) \)[/tex], confirming that this is the correct solution.

### Summary:

- The point of intersection of the given system of equations [tex]\( 3x - y = 12 \)[/tex] and [tex]\( x + 4y = 4 \)[/tex] is [tex]\( (4, 0) \)[/tex].
- The correct graph will show the two lines intersecting at the point [tex]\( (4, 0) \)[/tex].

Make sure to identify the graph that shows this intersection point.