Slimination
the teacher probably wants you to eliminate the x terms since there are an equal number of them
so multiply first equation by -1
-6x+3y=-30
add to second equation
6x-6x+3y+y=18-30
0x+4y=-12
4y=-12
divide by 4
y=-3
subsitute
6x+-3=18
add 3
6x=21
divide both sides by 6
x=21/6=7/2
x=7/2
y=-3
Step-by-step explanation:
x2+6x+9-9+y2-4y+4-4=23
(x+3)2-9+(y-2)2-4=23
(x+3)2+(y-2)2=36
center:(-3,2)
r:6
It’s is C. 3 because it makes sense