Hello : <span>3y = x + 6 ...(1) y – x = 3...(2) by (2) : y = x+3...(*) subsct in (1) : 3(x+3) = x+6 3x-x= -9+6 2x= -3 x=-3/2 subsct in (*) : y =-3/2 +3 =3/2</span>
Whats the question here if your wondering how many shells she finds in a certain amout of days just get a calculator and keep adding 12 over and over again
