Explanation:
If two bags of bird seed are used to fill these three bird feeders, then we can say that;
2 bags of bird seed = 3 bird feeders
To know the amount of bird seed that each feeder use, we will say;
x bags of bird seed = 1 bird feeder
Equating both postulates and solving
2 bags of bird seed = 3 bird feeders
x bags of bird seed = 1 bird feeder
Cross multiply
3 * x = 2 * 1
3x = 2
subtract 2 from both sides
3x - 2 = 2-2
3x - 2 = 0
Hence model that represents the situation us 3x - 2 = 0 where x is the number of bird seed that each feeder use.
Next is to solve for x;
3x - 2 = 0
3x = 2
x = 2/3
Hence each feeder used 2/3 bird seed