A student is using the elimination method to solve the system of equations #3x-y=5, 2x+3y=10#. What is the best first step method?
Multiply the first equation 3 so you create additive inverses with the y-terms.
The very BEST scenario you can have if you are using the elimination method is to have one of the variables being additive inverses. (same number but opposite signs)
In these two equations, note that the y-terms have opposite signs, but the numbers are different.
However, by multiplying equation A by 3, we will have additive inverses
Adding these two equations will cause the y-terms to add to 0, leaving only x terms, which can be solved.
So the BEST first step would be to make additive inverses by multiplying equation by 3.