Well you could do 5(60x+20y), 100(3x+y), and 2(150x+50y)
Well... One way you can do this is by testing a set of arrays and see the trend. If I chose to find what y1 is in (100, y1) and what y2 is in (101, y2), I would find the difference between y2 and y1. If y2 - y1 is positive, this means there is a positive relationship and y is also approaching POSITIVE infinity. A negative relation means that it is approaching NEGATIVE infinity. However, it could be approaching a single number like "4" for instance, and you just need to plug in the right number of data sets to make that educated guess.
Formula Example:
5 + 1 / (x + 1) will always approach 5 because "1 / (x + 1) will approach 0".
Hope this helps.
First, find the surface area of the bigger sides (there are 4 of them so what you get for one you will multiply by 4)
12 x 8 = 96
96 x 4 = 384
Then find the surface area of the smaller sides ( there are two small sides so multiply your answer by two)
8 x 8 = 64
64 x 2 =128
Then add both together
128 +384 = 512
Hope this helps :)
What you can do is start with the key details in it... the main ones are that the bacteria grows every 30 minutes, you start with 1 bacteria, and the end time is 180 minutes. Basically you know that 3 goes into 18 6 times so 30 goes into 180 6 times which means that if you started with 1 bacteria you will end up with 7. Understand?