2-74 ALGfefiRA. 



CASE 111. 

 When the quantities are unlike* 

 *RUL£. 



Setthem dovm- in a line, with their signs arid coef- 

 ficients prefixed. 



EXAMPLE. 



To 3^ ''^Sxy '\-2^a^—h'- 



Add zb -|-5 y — 9 



Sum 3fl-}-2^ — ^xy-\-^y'\' 2^/^* — b' — -9 



OTHER EXAMPLES IN ADDITION. 



* Here the first column is composed of like quantities, which 

 are added together by case i. The terms — 9^' and -f"9^' de- 

 stroy one another ; and the sum of — 12^' and 4-5^' is — 7^', 



by case 2, Tlie sum of ■^'^^ah and — ^^ ab is +3-v/<z3. 

 In like manner, -f 10 and — 6 together make -{-4 ; and the rest 

 of the terms being unlike, they are set down with their respect- 

 lYC signs and coefEcients prefixed, conformably to case 3. 



