15x-29xyz+19y(27a + 69y+3):2=

15x-29xyz+19y(27a + 69y+3):2= 15x-29xyz+19y(27a/2+69y/2+3/2)= =15x-29xyz+19y*27a/2+19y*69y/2+19y*3/2= =15x-29xyz+513a/2+1311y²/2+28,5y= =15x-29xyz+256,5a+655,5y²+28,5y