tolong dijawab dengan caranya plissssss

cara eliminasi
* x + 3y = 12                         *x + 3y = 12  |x1
 -x + 3y = 0                            -x + 3y = 0   |x-1
  ---------------- --                     = 1x + 3y = 12
 2x +     = 12                             1x - 3y = 0
 x = 12/2                                   ------------------- --
    = 6                                             6y  = 12
                                                        y = 12/6
                                                           = 2
jadikan jawaban yg terbaik yaa^^