MULTIPLICATION. 



In multiplication of algebraic quantities there is one 

 general rule for the signs ; namely, when the signs of the 

 factors are both affirmative or both negative, the product 

 is affirmative j but if one of the factors be affirmative and 

 the other negative, then the product is negative.* 



CASE 



* That like signs make +, and unlike signs — , in the prod- 

 uct, may be shewn thus : 



i. When 



