Solve the system of two linear equations.

−3x−4y=−23

3x−5y=5
(1 point)
Responses

(−5,−2)
left parenthesis negative 5 comma negative 2 right parenthesis

(5,−2)
left parenthesis 5 comma negative 2 right parenthesis

(−5, 2)
left parenthesis negative 5 comma 2 right parenthesis

(5, 2)

1 answer

To solve the system of equations:

  1. \(-3x - 4y = -23\) (Equation 1)
  2. \(3x - 5y = 5\) (Equation 2)

We can use either the substitution method or the elimination method. For this solution, let’s use the elimination method.

First, we can eliminate \(x\) by multiplying Equation 2 by 1 and adding it to Equation 1 after multiplying it by \( -1\):

Starting with:

  1. \( -3x - 4y = -23 \) (Equation 1)

Multiply Equation 2 by 1:

  1. \( 3x - 5y = 5 \) (Equation 2)

Now we multiply Equation 1 by -1:

-1 * (−3x - 4y = −23) → \( 3x + 4y = 23 \) (Equation 3)

Now we will add Equation 2 and Equation 3:

\[ (3x + 4y) + (3x - 5y) = 23 + 5 \] \[ 3x + 4y + 3x - 5y = 28 \] \[ 6x - y = 28 \]

Now let's isolate \(y\): \[ -y = 28 - 6x \] \[ y = 6x - 28 ; (Equation 4) \]

Now we can substitute \(y\) in Equation 2:

\[ 3x - 5(6x - 28) = 5 \] \[ 3x - 30x + 140 = 5 \] \[ -27x + 140 = 5 \] \[ -27x = 5 - 140 \] \[ -27x = -135 \] \[ x = 5 \]

Now we substitute \(x = 5\) back into Equation 4 to find \(y\): \[ y = 6(5) - 28 = 30 - 28 = 2 \]

Thus, the solution to the system of equations is:

\[ (x, y) = (5, 2) \]

So the answer is \((5, 2)\).