To eliminate a variable using the elimination method, you want to multiply one or both equations so that the coefficients of one of the variables match (or are opposites) when added together.
Let's analyze the given system of equations:
(Equation 1) (Equation 2)
To eliminate
To match the coefficients of
Now we can add this modified equation to Equation 1:
By observing the problem's answer choices, the factor we multiplied the second equation by is
c 2