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

1 answer

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

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

First, we will substitute equation 1 into equation 2:

Substituting \( x \) in equation 2: \[ (y - 4) + 8y = 2 \]

Combine like terms: \[ y - 4 + 8y = 2 \implies 9y - 4 = 2 \]

Now, add 4 to both sides: \[ 9y = 6 \]

Now, divide by 9: \[ y = \frac{6}{9} = \frac{2}{3} \]

Next, we will substitute the value of \( y \) back into equation 1 to find \( x \): \[ x = y - 4 = \frac{2}{3} - 4 \]

Convert 4 to a fraction with the same denominator: \[ 4 = \frac{12}{3} \]

So, we have: \[ x = \frac{2}{3} - \frac{12}{3} = \frac{2 - 12}{3} = \frac{-10}{3} \]

Thus, the solution to the system is: \[ \left( -\frac{10}{3}, \frac{2}{3} \right) \]

Based on the options provided, the correct choice corresponding to the values we found is: \[ \left( -\frac{10}{3}, \frac{2}{3} \right) \]