Answer:
Explanation:
To use elimination method, we need to eliminate one of the variables (x or y) by adding or subtracting the two equations. To do this, the coefficients of one of the variables in the two equations should be the same or opposite.
Looking at the two equations:
Equation #1: 2x + 18y = -9
Equation #2: 4x + 18y = -27
We can see that the coefficients of y are already the same in both equations. So, we can eliminate y by subtracting Equation #1 from Equation #2.
However, to do this we need to make sure that the coefficients of x in the two equations are opposites, i.e., one is positive and one is negative.
Therefore, the first step we could take to solve this system using elimination is to multiply Equation #1 by -2 to get:
-4x - 36y = 18
Now the coefficients of x in the two equations are opposites, so we can subtract Equation #1 from Equation #2 to eliminate y and solve for x.
So, the correct answer is:
Multiply equation #1 by -2.