Solve using elimination.

-3x-3y=3
3x+6y=18

1 answer

To solve the system of equations using the elimination method, we start with the following equations:

  1. \(-3x - 3y = 3\)

  2. \(3x + 6y = 18\)

Next, we can manipulate the equations to eliminate one variable. A convenient way to eliminate \(x\) is to add the two equations together, but first, let's manipulate the first equation so we can see if we can easily eliminate \(x\):

  1. \(-3x - 3y = 3\) can be simplified by dividing every term by -3:

\[ x + y = -1 \quad \text{(Equation 1')} \]

Now, we can rewrite the second equation:

  1. \(3x + 6y = 18\) can be simplified by dividing every term by 3:

\[ x + 2y = 6 \quad \text{(Equation 2')} \]

Now, we have a new system of equations:

1') \(x + y = -1\)

2') \(x + 2y = 6\)

Next, we'll eliminate \(x\) by subtracting equation 1' from equation 2':

\[ (x + 2y) - (x + y) = 6 - (-1) \]

This simplifies to:

\[ 2y - y = 6 + 1 \] \[ y = 7 \]

Now that we have \(y\), we can substitute it back into equation 1' to find \(x\):

\[ x + 7 = -1 \] \[ x = -1 - 7 \] \[ x = -8 \]

Thus, the solution to the system of equations is:

\[ \boxed{(-8, 7)} \]