Question

2/x+3/y=9/xy,4/x+9/y=21/xy
solve for x and y bybusing substitution method​

Answer 1

Answer:

Multiplying both sides by xy, we get :

2y + 3x = 92y+3x=9

4y + 9x = 214y+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)(4y+9x)−2(2y+3x)=21−2(9)

= > 3x = 21 - 18 = 3=>3x=21−18=3

= > x = 1=>x=1

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

2y + 3 = 92y+3=9

= > 2y = 6=>2y=6

= > y = 3=>y=3

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