Use the substitution method to solve the system x=y−4, x+8y=2

.(1 point)
Responses

(23,−313)

left parenthesis Start Fraction 2 over 3 End Fraction comma negative 3 Start Fraction 1 over 3 End Fraction right parenthesis
(−313,23)
left parenthesis negative 3 Start Fraction 1 over 3 End Fraction comma Start Fraction 2 over 3 End Fraction right parenthesis
infinite solutions
infinite solutions
no solution

1 answer

To solve the system of equations using the substitution method, we start with the two equations:

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

We can substitute the expression for \( x \) from the first equation into the second equation.

Substituting \( x \) in the second equation:

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

Now, combine like terms:

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

To isolate \( y \), add 4 to both sides:

\[ 9y = 6 \]

Now, divide both sides by 9:

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

Next, substitute \( y \) back into the first equation to find \( x \):

\[ x = \left( \frac{2}{3} \right) - 4 \] \[ x = \frac{2}{3} - \frac{12}{3} = -\frac{10}{3} \]

Now we have the solution:

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

Thus, the solution to the system of equations is:

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

Among the provided responses, it seems "left parenthesis negative 3 Start Fraction 1 over 3 End fraction comma Start Fraction 2 over 3 End fraction right parenthesis" corresponds to your solution as \(-\frac{10}{3}\) can be written as \(-3 \frac{1}{3}\).

Hence, the correct answer is:

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