Answer:
25%
Step-by-step explanation:
Discount = 1600 - 1200 = 400
Percentage discount

Multiple values of y for a single value of x is a sure giveaway that this is NOT a function. Please review definitions of "function." A function would be represented if no x value has more than one y value associated with it.
Answer:
b)
a)
a)
Step-by-step explanation:
hope this helps i havent done this in a while
Answer:
15
Step-by-step explanation:
18 . ( 14 - 9 ) ÷ [ 12 - ( 19 - 13 ) ]
18 . ( 5 ) ÷ [ 12 - 6 ]
90 ÷ 6
15
It is easier (for me anyway) to find 10% then work around that.
Following that path would mean that, by making a table:
100% = 220
10% = 22
5% (Which is half the 10) = 11