SIMPLE EQTTATIONS. 343 



EXAMPLES. 



1. Given \ 3-^+5;' = 407 ,^ ^^^^ ^ ^^j 



First, multiply the second equation by 3, 

 And we shall have 3^+6)' = 42 ; 

 Then, from this last equation subtract the first. 

 And it will give 6y — 5)=42 — 40, or;' =2, 

 Atid therefore, x= 14 — 2y=: 14 — 4= 10. 



2. Given s ^^"T^-^'"^ ^ f ; to find x and y. 



^2^+5jy=i6 3 •" 



Let the first equation be raultiplied by 2, and the sec- 

 ond by ^, 



And we shall have loAT — • 6y^ 18 



IOA*-j-25^= ^^ » 



And if the former of these be subtracted from the latter. 

 It will give 31;' = 62, or y=:~^:=2, 



9"4"3v 

 And consequently, x:=: ^> by the fipst equation, 



5 ' ^ 



Another Method. 



Multiply the first equation by ^, and the second by 3, 



And we shall have 25^ — 15^ = 4^ 

 6a:-}-i5;; = 48 ; 

 Now,, let these equations be added together, 



And it will give 3i,v=93, or .v = -|-J-= 3» 



f6— 2v 

 And consequently, yz=L y by the second equation, 



16—6 



Or >•=; =: y =r2, as before. 



MlSCELLANEOUi 



