Answer:
A
Step-by-step explanation:
Lets first solve the relation for "y". Shown below:

This is clearly an equation of a line in the form 
It will be a negatively sloped line, when graphed.
We can use vertical line test to determine function or relation. If a vertical line passes through only 1 point in the graph, we say that it is a function.
Think of a negatively sloped line. No matter where you draw a vertical line, it will only cut the line at 1 point.
So, this is definitely an equation of a function
Correct answer is A
Answer:
2% profit
Step-by-step explanation:
x = price
50kg = 50x
30kg => 35x
20kg => 16x
35x + 16x = 51x
51x - 50x = x
50x .............. 100%
x ...................... p%
p = 1×100/50 = 100/50 = 2%
Answer:
21:126
6:36
1:6
Step-by-step explanation:
12*2=24
24*3=72
72*4=288
288*5=1440
First question:b
Second question:c