Question

3x + 5y = 9 and 5x + 3y = 7. what is the value of x-y​

Answer 1

Answer:

-1

Step-by-step explanation:

16y = 24

y = 24/16

= 3/2

3x= (18 - 15)/2

=3/2

x= 1/2

x-y = 1/2-3/2

= (1-3)/2

=-1

Answer 2

Answer:

The value of $x$ -  $y$  is -1

Step-by-step explanation:

3$x$ + 5$y$ = 9    ----> equation 1 (eqn 1)

5$x$ + 3$y$ = 7    ----> equation 2 (eqn 2)

5 x (eqn 1) : 5(3$x$ + 5$y$ = 9)

3 x (eqn 2) : 3(5$x$ + 3$y$ = 7)

15$x$ + 25$y$ = 45    (cancel 15$x$ from both the equations)

15$x$ + 9$y$ = 21

25$y$  - 9y = 45 - 21

16$y$  = 24  ,  $y$  = $\frac{24}{16}$ = $\frac{3}{2}$ = 1.5

Substitute $y$  = 1.5 in eqn 1:

3$x$ + 5(1.5) = 9

3$x$ = 9 - 7.5

$x$ = $\frac{1.5}{3}$ = $\frac{1}{2}$ = 0.5

Solve the equation $x$ -  $y$  

$x$ -  $y$  

= 0.5 - 1.5 = -1