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Solving Equations Using Substitution Quick Check
4 of 54 of 5 Items

Question
Solve the system of equations.
−4x+6y=38

x−5y=−20
(1 point)
Responses

(35, −3)
left parenthesis 35 comma negative 3 right parenthesis

(5, 3)
left parenthesis 5 comma 3 right parenthesis

(−35, −3)
left parenthesis negative 35 comma negative 3 right parenthesis

(−5, 3)

1 answer

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

  1. \( -4x + 6y = 38 \)
  2. \( x - 5y = -20 \)

First, let's solve the second equation for \( x \):

\[ x = 5y - 20 \]

Now we can substitute this expression for \( x \) into the first equation:

\[ -4(5y - 20) + 6y = 38 \]

Distribute \(-4\):

\[ -20y + 80 + 6y = 38 \]

Combine like terms:

\[ -14y + 80 = 38 \]

Now, isolate \( y \):

\[ -14y = 38 - 80 \] \[ -14y = -42 \] \[ y = \frac{-42}{-14} = 3 \]

Now that we have \( y \), we can substitute back to find \( x \):

\[ x = 5(3) - 20 \] \[ x = 15 - 20 \] \[ x = -5 \]

So the solution to the system of equations is \( (x, y) = (-5, 3) \).

The correct response is:

(−5, 3).