Explanation:
You want to first to substitute to form 3 equations.
5=4a+2b+c
12=9a+3b+c
-4=a-b+c
Now solve with whatever way you fell comfortable, I'm going to use elimination.
First eliminate c
7=5a+b
16=8a+4b --> 4=2a+b
Then I'll eliminate b,
3=3a
a=1
Now solve for b and c
7=5+b
b=2
1-2+c=-4
c=-3
Now for the equation:
y=x^2+2b-3
Hope this helps!
