Question

solve fast X + Y is equal to zero 2 x minus Y is equal to 9​

Answer 1

• x = 3
• y = - 3

Answer:

method used : $\boxed{ \: Elimination \: \: method \: }$

We have,

• x + y = 0 ———————( 1 )
• 2x - y = 9 -——————( 2 )

Adding these equations ( 1 ) and ( 2 ) , we get :

$\: \: \: \: \: \: x \: \cancel{ + y} = 0$

$\: \: \: \: \: 2x \: \cancel{ - y} = 9$

——————————————

$\Rightarrow 3x = 9$

——————————————

$\Rightarrow \cancel{3} x = \cancel{9} \: {}^{3}$

$\Rightarrow x = 3$

On substituting x = 3 in equation ( 1 ), we get :

$\longmapsto 3 + y = 0$

$\Rightarrow y = - 3$

Hence,

• x = 3
• y = - 3

Answer 2

Answer:

X = 3 and Y = -3

Explanation:

Given pair of equations are

              $x + y = 0\\2x - y = 9$

Now, By adding both the equations we obtain

                            $3x = 9\\x = 3$

substituting x = 3 in the first equation we get y = -3.