Question

Solve the system of two equations using elimination with multiplication.
4x−6y=−48

−2x+4y=30
(1 point)
Responses

(−21,−6)
left parenthesis negative 21 comma negative 6 right parenthesis

(−3, 6)
left parenthesis negative 3 comma 6 right parenthesis

(−33,−9)
left parenthesis negative 33 comma negative 9 right parenthesis

(3, 9)

1 answer

To solve the system of equations using elimination, we start with the given equations:

  1. \( 4x - 6y = -48 \)
  2. \( -2x + 4y = 30 \)

Let's first align them for easier manipulation:

\[ 4x - 6y = -48 \quad (1) \] \[ -2x + 4y = 30 \quad (2) \]

To eliminate one of the variables, we can multiply equation (2) by a factor that will allow us to add or subtract it from equation (1) to eliminate one of the variables.

We can multiply equation (2) by 2:

\[ 2(-2x + 4y) = 2(30) \]

This gives us:

\[ -4x + 8y = 60 \quad (3) \]

Now, we will add equations (1) and (3):

  1. \( 4x - 6y = -48 \)
  2. \( -4x + 8y = 60 \)

Adding the two equations:

\[ (4x - 4x) + (-6y + 8y) = -48 + 60 \] \[ 0 + 2y = 12 \] \[ 2y = 12 \] \[ y = 6 \]

Now that we have \( y = 6 \), we can substitute this value back into one of the original equations to solve for \( x \). We'll use equation (1):

\[ 4x - 6(6) = -48 \] \[ 4x - 36 = -48 \] \[ 4x = -48 + 36 \] \[ 4x = -12 \] \[ x = -3 \]

The solution to the system of equations is:

\[ (x, y) = (-3, 6) \]

The correct answer from the given options is:

(−3, 6)