I disagree because elimination is by far faster and simpler than using substitution to solve the system.
Work Step by Step
Our two equations are: 1. y-3x=4 2. y-6x=12 Using elimination is easier because I can eliminate the y-terms by merely subtracting the first equation from the second. Then I can solve for x and then use that value of x to find the value of y by substituting it back to one of the original equations. If I use substitution, I would have to first solve for one of the variables and then I can substitute it into one of the equations whereas by using elimination, I can eliminate the y-terms by just using subtraction.