Graph the following system of equations:

[tex]
\begin{array}{l}
2x + 3y = 12 \\
2x + 6y = 18
\end{array}
[/tex]

What is the solution to the system?

A. There is no solution.
B. There is one unique solution, [tex]$(0,4)$[/tex].
C. There is one unique solution, [tex]$(3,2)$[/tex].
D. There are infinitely many solutions.



Answer :

To solve the given system of equations, let's break it down step by step.

1. Write down the system of equations:
[tex]\[ \begin{cases} 2x + 3y = 12 \\ 2x + 6y = 18 \end{cases} \][/tex]

2. Simplify the equations, if possible:
Notice that the second equation can be simplified. If we divide the entire equation by 2:
[tex]\[ \frac{2x + 6y}{2} = \frac{18}{2} \][/tex]
This simplifies to:
[tex]\[ x + 3y = 9 \][/tex]
However, for consistency, we can write it back in terms of 2x:
[tex]\[ 2x + 6y = 18 \][/tex]

3. Subtract the first equation from the second equation to eliminate \(2x\):
[tex]\[ (2x + 6y) - (2x + 3y) = 18 - 12 \][/tex]
This simplifies to:
[tex]\[ 3y = 6 \][/tex]
Solving for \(y\):
[tex]\[ y = 2 \][/tex]

4. Substitute \(y = 2\) back into the first equation to solve for \(x\):
[tex]\[ 2x + 3(2) = 12 \][/tex]
[tex]\[ 2x + 6 = 12 \][/tex]
[tex]\[ 2x = 6 \][/tex]
[tex]\[ x = 3 \][/tex]

Therefore, the solution to the system of equations is \((3, 2)\).

5. Verify the solution:
Substitute \(x = 3\) and \(y = 2\) back into the original equations to ensure they are satisfied:
- For the first equation:
[tex]\[ 2(3) + 3(2) = 6 + 6 = 12 \quad \text{(True)} \][/tex]
- For the second equation:
[tex]\[ 2(3) + 6(2) = 6 + 12 = 18 \quad \text{(True)} \][/tex]

Since both equations are satisfied by \( (3, 2) \), this is indeed the solution.

Therefore, the solution to the system of equations is the unique point \((3, 2)\).

- There is one unique solution, [tex]\( (3, 2) \)[/tex].