Answer:
y-11
Step-by-step explanation:
First you divide 3 by 3 to get one. Then you add 12 to -1 to get 11. Then you will have y-11. PEMDAS saves lives.
Now, let's do the same as we did for the previous one here.

notice again, how did we get 84 for the 4th element's coefficient? well 36 * 7 / 3. and so on. And you can just expand it from there.
What are you solving for? if you are solving for x, then x=(P-12)/(Q-13)
Answer:
Walmart: 1.20 divided by 3= 0.4
Sprouts: 1.35 divided by 5= 0.27
Sprouts has a better deal