Question

x + y = 0 ; 2x - y = 9​

Answer 1

Answer:

x=3

y=-3

Explanation:

x+y=0-(i)

2x-y=9-(ii)

According to the question

x+y=0

x= -y

Putting the value of x in equation (ii)

2x-y=9

2(-y)-y= 9

-2y-y=9

-3y=9

-y=9/3

-y=3

y=-3

Putting the value of y in equation (i)

x+y=0

x+(-3)=0

x-3=0

x=3

Hence the value of x and y are 3 and -3

or

Adding both equation

x+y=0

2x-y=9

----------

3x=9

x=9/3

x=3

Putting the value of x in equation (i)

x+y=0

3+y=0

y= -3

Hence the value of x and y are 3 and -3