Answer: A
Step-by-step explanation:
The easiest method to solve this system of equations would be to use substitution method because y is already solved for.
[tex]-4x+6(-2x+21)=-18[/tex] [distribute]
[tex]-4x-12x+126=-18[/tex] [combine like terms]
[tex]-16x+126=-18[/tex] [subtract both sides by 126]
[tex]-16x=-144[/tex] [divide both sides by -16]
[tex]x=9[/tex]
Now, we plug x into the second equation to get y.
[tex]y=-2(9)+21[/tex] [multiply]
[tex]y=-18+21[/tex] [combine like terms]
[tex]y=3[/tex]
Putting (x,y), we get (9,3).
