Question

3x+9y=9
4x-9y=12
Solving systems by elimination

Answer 1

(x,y)=(3,0)

Explanation:

`\left \{ {{3x+9y=9} \atop {4x-9y=12}} \right.`

⇒ 7x=21 divide both sides of the equation by 7

⇒ x=3

then put x=3 in the equation 3x+9y=9

⇒ 3×3+9y=9

⇒ 9+9y=9

⇒ 9y=9-9

⇒ 9y=0 divide both sides of the equation by 9

⇒ y=0

(x,y)=(3,0)

⇒
`\left \{ {{3*3+9*0=9} \atop {4*3-9*0=12}} \right.`

⇒
`\left \{ {{9=9} \atop {12=12}} \right.`

⇒ (x,y)=(3,0)

Answer 2

x=3 y=0

hope this helps!