Question

Solve for x and y.
2/x + 3/y = 9/xy ;
4/x +9/y = 21/xy

Answer 1

Heya


Multiplying both sides by xy, we get :

$2y + 3x = 9$
$4y + 9x = 21$

Now, multiplying the first equation by (2) and subtracting from the second one, we get :

$(4y + 9x) - 2(2y + 3x) = 21 - 2(9)$

$= > 3x = 21 - 18 = 3$

$= > x = 1$

Hence, substituting the value in either equation and solving for y, we get :

$2y + 3 = 9$

$= > 2y = 6$
$= > y = 3$


Hence, we get : ( x , y ) = ( 1 , 3 ) as the solution

Answer 2

SOLUTION:-
2/x + 3/y = 9/xy . 4/x +9/y = 21/xy

(3x+2y)xy =9/xy , (9x+4y) = 21/xy

3x+2y = 9 .......(1) , 9x+4y = 21..........(2)

maltiply by eq(1)×3 -eq(2)

9x+6y = 27
9x+4y = 21
______________ subtraction
2y = 6
y = 3

y's value puting in eq(1)

3x+2×3= 9

3x = 9-6

x= 3/3
x =1

(x,y)=(1,3)ans