Question

For the system 3x - 5y = 9 and 2x + y = 3, which variable should you eliminate first and why? How will you eliminate that variable?

A) Eliminate x first by multiplying the second equation by 3 and adding it to the first equation.
B) Eliminate y first by multiplying the first equation by 2 and subtracting it from the second equation.
C) Eliminate y first by multiplying the second equation by 5 and adding it to the first equation.
D) Eliminate x first by multiplying the first equation by 5 and adding it to the second equation.

Answer 1

To eliminate y in the given system of equations, you should multiply the first equation by 2 and subtract it from the second equation.

Step-by-step explanation:

To eliminate a variable in a system of equations, we want to manipulate the equations such that the coefficients of one variable in both equations are the same or multiples of each other. In this case, the coefficients of the variable y in both equations are already the same (1), so we can eliminate y by subtracting the second equation from the first equation. This will result in eliminating the y variable. The correct answer is option B:

• Eliminate y first by multiplying the first equation by 2 and subtracting it from the second equation.