Solve: 6x + 3y = 7xy and 3x + 9y = 11xy.

The given equations are 6x + 3y = 7xy and 3x + 9y = 11xy.


Dividing by xy on both sides of the given equations, we get




Then,


… (1)


… (2)


If we substitute and in (1) and (2), we get


3p + 6q = 7 … (3)


9p + 3q = 11 … (4)


Now by elimination method,


Step 1: Multiply equation (3) by 3 and equation (4) by 1 to make the coefficients of x equal.


Then, we get the equations as:


9p + 18q = 21 … (5)


9p + 3q = 11 … (6)


Step 2: Subtract equation (6) from equation (5),


(9p – 9p) + (3q – 18q) = 11 – 21


- 15q = - 10



Step 3: Substitute q value in (3),



3p = 3


p = 1


We know that and .


Substituting values of p and q, we get


x = 1 and y =


The solution is x = 1 and y = .


12