Will reward the best answer brainliest. Use elimination method to solve
-3x + 3y = 4
-x + y = 3​

No solution

to eliminate a variable you need to multiple the second equation by either a 3 and then subtract the two equations or by a -3 and add the two equations.
after changing it, instead of eliminating only one variable, both variables are eliminated and there is no solution

i hope this makes sense, not sure how else to explain