Question

Francine solves the system of equations using the linear combination method.

4x+3y=−1
3x−5y=4
Which steps would allow her to eliminate the x terms in the system of equations?


A. Multiply 4x+3y=−1 by 3. Multiply 3x−5y=4 by −4 . Add the resulting equations together.

B. Multiply 4x+3y=−1 by 4. Multiply 3x−5y=4 by 3. Add the resulting equations together.

C. Multiply 4x+3y=−1 by 5. Multiply 3x−5y=4 by 3. Add the resulting equations together.

D. Multiply 4x+3y=−1 by −4 . Multiply 3x−5y=4 by 3. Add the resulting equations together.

Answer 1

C is the correct answer.

Answer 2

Multiply 4x+3y=−1 by 3. Multiply 3x−5y=4 by −4 . Add the resulting equations together.

Explanation:

Given the simultaneous equation below:

4x+3y=−1 ...(1) × 3

3x−5y=4 ...(2) × -4

Using elimination method to solve the problem,

Before we can eliminate x, the coefficient of x in both equation must have similar whole number as coefficient.

To make the coefficient equal, we will multiply equation 1 by 3 and equation 2 by -4 as shown above

The equations will then become

12x+9y = -3

-12x+20y = -16

Then we will add the resulting simultaneous equations.

The steps that would allow her to eliminate the x terms in the system of equations is to "Multiply 4x+3y=−1 by 3. Multiply 3x−5y=4 by −4 . Add the resulting equations together"