Answer:
13.
y=-3x²
Step-by-step explanation:
y=ax²+bx+c
0=0+0+c,c=0
so y=ax²+bx
-3=a+b
-12=4a+2b
or -6=2a+b
subtract
-3+6=a+b-2a-b
-a=3
a=-3
-3+b=-3
b=0
when x=3
y=-3×3²=-27
when x=4
y=-3×4²=-48
whih is true.
