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

Responses

no solution
no solution

infinite solutions

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

(−3 1/3,2/3)

1 answer

To solve the system of equations using the substitution method, we need to substitute the expression for \( x \) from the first equation into the second equation.

The system of equations is:

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

Step 1: Substitute the first equation into the second equation.

Substituting \( x \) in the second equation:

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

Step 2: Combine like terms.

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

\[ 9y - 4 = 2 \]

Step 3: Solve for \( y \).

Add 4 to both sides:

\[ 9y = 6 \]

Now divide by 9:

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

Step 4: Substitute \( y \) back into the first equation to solve for \( x \).

Using \( y = \frac{2}{3} \):

\[ x = y - 4 \]

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

Convert 4 to a fraction with a denominator of 3:

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

Step 5: Write the solution as an ordered pair.

The solution to the system of equations is:

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

However, looking at the provided responses, it appears that the point \((−3 \frac{1}{3}, 2/3)\) can be expressed as \((- \frac{10}{3}, \frac{2}{3})\).

Thus, the answer is:

(−3 1/3, 2/3)