Question 60176
Hello Lisa,


The given system of equations are :


3x - 4y = 8 ------------ (1) 


6x - 2y = 10 ------------ (2)


To solve them by addition or subtraction,  we equalise any one of the terms. That is either the x or the y.


So, we multiply equation (2) by 2 and subtract equation (1) from (2).


12x - 4y  = 20 

3x - 4y  = 8

-   +      - 
--------------- 

9x = 12 


==> x = 4/3


Plugging this value in one of the above equation, we get the value of y.


3x - 4y = 8 


3(4/3) - 4y = 8 


4 - 4y = 8 


4 - 8 = 4y 


-4 = 4y 


This implies y = -1 


Hence, the answer.