Question

He elimination method is ideal for solving this system of equations. By which number must you multiply the second equation to eliminate the y-variable, and what is the solution for this system?

x + 3y = 42
2x − y = 14

A.
Multiply the second equation by -3. The solution is x = 12, y = 9.
B.
Multiply the second equation by -2. The solution is x = 12, y = 10.
C.
Multiply the second equation by 2. The solution is x = 15, y = 9.
D.
Multiply the second equation by 3. The solution is x = 12, y = 10.

Answer 1

D. Multiply the second equation by 3. The solution is x = 12, y = 10.

Explanation:

First, look at the y variable of the first equation. It is 3y.

To solve by elimination, the variables have to add together to 0.

So, -3y needs to be added to -3y to eliminate the y variable.

The second equation has the y variable of -y, so it has to be multiplied by 3.

So, answer choice D is the correct answer.