Question

5x+3y=7and 3x+5y=9 then find the value of x-y​

Answer 1

Answer:

x+y= 2

Step-by-step explanation:

Given eqn

3x+5y=9

5x+3y=7

In order to eleminate “x”we need to make the co-efficient of “x” same on both the equation.

To achieve this

we will multiply 5 with equation 1

And multiply 3 with equation 2

On multiplication it will look like….

15x+25y=45

15x+9y=21

Now we will substract equation 1 and 2, it will give,

16y=24

y=1.5

Now, we will put y = 1.5 in equation 1 and solve

Upon solving we get,

x=0.5

Now, we got both x and y.

So, x+y=0.5+1.5=2

Answer 2

Answer:

3x+5y=9 …(1)

5x+3y=7 …(2)

Let us simplify the equations by eliminating a variable

Make the coefficients of X or Y equal

Multiply equation (1) with 5 and equation (2) with 3

We get 15x+25y=45 and 15x+9y=21

Now subtract the equations, we get

(15x+25y)-(15x+9y)=(45–21)

16y=24, y= 24/16 = 3/2

Substituting the value of y in equation (1) we get

3x+5(3/2)=9

3x+15/2=9

3x=9–15/2

3x=3/2

x =1/2

x+y =3/2+1/2= 2

x+y=2

The other method is simply add equations (1) & (2)

You get

8x+8y=16

x+y = 2

Step-by-step explanation: