Answer:
(x,y)=(3,0)
Step-by-step explanation:
[tex]\left \{ {{3x+9y=9} \atop {4x-9y=12}} \right.[/tex]
⇒ 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)
⇒ [tex]\left \{ {{3*3+9*0=9} \atop {4*3-9*0=12}} \right.[/tex]
⇒ [tex]\left \{ {{9=9} \atop {12=12}} \right.[/tex]
⇒ (x,y)=(3,0)
