Use the substitution method to solve the system x=y−4 , x+8y=2 .(1 point)

Responses

(−313,23)
left parenthesis negative 3 Start Fraction 1 over 3 End Fraction comma Start Fraction 2 over 3 End Fraction right parenthesis

(23,−313)
left parenthesis Start Fraction 2 over 3 End Fraction comma negative 3 Start Fraction 1 over 3 End Fraction right parenthesis

no solution
no solution

infinite solutions

1 answer

To solve the system of equations using the substitution method, we have the following equations:

  1. \( x = y - 4 \)
  2. \( x + 8y = 2 \)

Let's substitute the expression for \( x \) from the first equation into the second equation.

Substituting \( x = y - 4 \) into the second equation:

\[ (y - 4) + 8y = 2 \]

Now, simplify this equation:

\[ y - 4 + 8y = 2 \] \[ 9y - 4 = 2 \]

Next, add 4 to both sides:

\[ 9y = 6 \]

Now, divide by 9 to solve for \( y \):

\[ y = \frac{6}{9} = \frac{2}{3} \]

Now that we have \( y \), we can find \( x \) using the first equation:

\[ x = y - 4 = \frac{2}{3} - 4 \] \[ x = \frac{2}{3} - \frac{12}{3} = \frac{2 - 12}{3} = \frac{-10}{3} \]

So the solution is:

\[ \left( \frac{-10}{3}, \frac{2}{3} \right) \]

This means that the correct response is:

\[ \left( -\frac{10}{3}, \frac{2}{3} \right) \]

However, when we compare this to the provided response options, \( \left( -3 \frac{1}{3}, \frac{2}{3} \right) \) appears to represent the same value as \( -\frac{10}{3} \), thus making the correct response as:

\[ \left( -3 \frac{1}{3}, \frac{2}{3} \right) \]

So, the correct answer is:

\((-3 \frac{1}{3}, \frac{2}{3})\).