−9x+y= \,\,71 71 -x-y= −x−y= \,\,-1 −1 \mathbf{Add}\text{ to eliminate }\mathbf{y.}Add to eliminate y. \mathbf{Subtract}\text{ t
o eliminate }\mathbf{x.}Subtract to eliminate x. \mathbf{Subtract}\text{ to eliminate }\mathbf{y.}Subtract to eliminate y. \mathbf{Add}\text{ to eliminate }\mathbf{x.}Add to eliminate x.
Using elimination method we can eliminate y first since they have the same coefficient.
To do that we will need to add up both equations. We are adding because the coefficient of y in both equations has different signs. If they have the same sign, we would have subtracted.
<em>Hence the correct option in this case is to add to eliminate y.</em>
