Answer:
$9
Explanation:
First, we need to find 70% of the original price of $30 using the following equation:

It means that Emma pays $21 less than the original price. So, she pays:
$30 - $21 = $9
Therefore, the answer is $9
Answer:
no
Step-by-step explanation:
if the ratio (yx) of two variables (x and y) is equal to a constant (k=yx) .in this case y is said to be directly proportional to x with proportionality constant k
9$ for three cans then 9/3= 3 $ per can