Step-by-step explanation:
simply the first one.
-9x -6y = 39 is nothing else than
3x + 2x = -13 multiplied by -3
which leaves the values and solutions unchanged, as we could simply divide by -3 again and end up with the original system and its solution.
I think it’s nonlinear and increasing
5.12 x 10*
(the * should be a little number 4 in the corner)