Adding what rational expressions?
It would take her around 37 minutes, I divided 486 by 195 and got 2.5, basically. I then timed that by 15 and got 37
You should guess.e.g y=3 x=0 or y=5 x=3.
To make the full recipe, you need 3/8 cup of milk. Multiply this value by 1/2 to figure out how much of this is needed for only half the recipe
(1/2)*(3/8) = (1*3)/(2*8) = 3/16
So you'll need 3/16 cup of milk to make one-half of the recipe