A treatise on algebra

A treatise on algebra: Fundamental Laws Part1
WE have said that all concrete quantities must be measured by the number of times each contains some unit of its own kind. Now a sum of money may be either a receipt or a payment, it may be either a gain or a loss ; motion along a given straight line may be in either of two opposite directions ; time may be either before or after some particular epoch ; and so in very many other cases. Thus many concrete magnitudes are capable of existing in two diametrically opposite states: the question then a Read More...
A treatise on algebra: Fundamental Laws Part2
If we are considering the amount of a man's gains, -f 4 will stand for what increases his total gain, that is, + 4 will stand for a gain of 4 ; so also 4 will stand for what decreases his total gain, that is, 4 will stand for a loss of 4. If however we are calculating the amount of a man's losses, + 4 will stand for a loss of 4, and 4 will stand for a gain of 4. Again, if the magnitude to be increased or diminished is the distance from any particular place, measured in any particular d Read More...