“select best answer for the question” what is 4c ?

Because of your favorite lemonade it is $3.84 for 3 gallons. write this as an unit rate

X+y=-4 x-y=2 use elimination with adding and subtraction

What is the missing statement in step 4? ? rts ? ? vtu and ? rtu ? ? vts ? rts ? ? rvs and ? rtu ? ? stv ? vrs ? ? vru and ? usr ? ? usv ? vur ? ? vus and ? uvs ? ? sru