Solve the system of two equations using elimination with multiplication.

4x−6y=−48

−2x+4y=30
(1 point)
Responses

(3, 9)
left parenthesis 3 comma 9 right parenthesis

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

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

(−3, 6)

1 answer

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

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

Step 1: Align the equations

We have: \[ 4x - 6y = -48 \tag{1} \] \[ -2x + 4y = 30 \tag{2} \]

Step 2: Multiply the equations if necessary

We want to eliminate one of the variables. Let's eliminate \( x \) by making the coefficients of \( x \) the same. To do this, we can multiply the second equation by \( 2 \) to match the coefficient of \( x \) in the first equation:

\[ 2(-2x + 4y) = 2(30) \] This gives us: \[ -4x + 8y = 60 \tag{3} \]

Step 3: Add the equations

Now we can add equation (1) and the modified equation (3): \[ (4x - 6y) + (-4x + 8y) = -48 + 60 \] This simplifies to: \[ 2y = 12 \] Now, divide both sides by \( 2 \): \[ y = 6 \]

Step 4: Substitute \( y \) back into one of the original equations to find \( x \)

We can substitute \( y = 6 \) back into the first equation: \[ 4x - 6(6) = -48 \] This simplifies to: \[ 4x - 36 = -48 \] Now, add \( 36 \) to both sides: \[ 4x = -48 + 36 \] \[ 4x = -12 \] Now, divide by \( 4 \): \[ x = -3 \]

Solution

The solution to the system of equations is \( (x, y) = (-3, 6) \).

Thus, the correct answer is (−3, 6).