First, we have to to take away the weight at birth from the current weight. This is so we can actually see what he has <em>gained</em> from his birth onward.
538 - 132 = 406
Next, divide 406 by the number of months, so we can see how much weight he gained each month.
A b c d... and x are all representing 1 unknown #. The particular letter is not revelent unless its like f (x) =.... which just means y but g(x) sometimes means graph. otherwise it doesn't matter at all
