The answer should be option c
So what you have to do to figure this out is 47-20 to get 27, then take 27 and divide it by 3 to get the answer of 9 comic books were sold by John.
12 ribbons
p.s: im in 7th grade so you can trust me
Answer: 
Step-by-step explanation:
To find the inverse, we want to switch the y with x and x with y. Once we do that, we solve for y.
[switch x and y]
[subtract both sides by 3]
[multiply both sides by 2]

Now, we know that
.
Answer:
x = 27
y = 29
Step-by-step explanation: