The answer for this should be 50 but I don’t know how could someone tell me why it’s $50?

Answer:
50
Step-by-step explanation:
So say the bill is x.
18% of x = 0.18x
0.18x = 9
x = 50
Answer:
it is 50
Step-by-step explanation:
you have to do 9 x 10/18