what is the solution to this system of equations?

3x + y = 30
x - 3y = 0

1 answer

To solve the system of equations:

  1. \(3x + y = 30\)
  2. \(x - 3y = 0\)

We can use the substitution or elimination method. Here, I will use substitution.

From the second equation, we can express \(x\) in terms of \(y\):

\[ x = 3y \]

Now we can substitute \(x\) in the first equation:

\[ 3(3y) + y = 30 \]

This simplifies to:

\[ 9y + y = 30 \]

Combine like terms:

\[ 10y = 30 \]

Now, divide both sides by 10:

\[ y = 3 \]

Now that we have \(y\), we can substitute it back into the equation \(x = 3y\) to find \(x\):

\[ x = 3(3) = 9 \]

Thus, the solution to the system of equations is:

\[ x = 9, \quad y = 3 \]

Or in ordered pair notation:

\[ (9, 3) \]