Question

(2,14),(1,-1),(3,35)

Find the quadratic function y=ax^2+bx+c

1) 4a+2b+c=14
2) a+b+c=-1
3) 9a+3b+c= 35

equation 1&2 = 3a + b = 13
equation 1&3 = -5a +5b = -21

i know you take those two equations now

3a + b = 13
-5a - 5b = -21

multiply the top by 5 and the bottom equation by 3

15a + 5b = 65
-15a - 15b = -63
that
-10b = 2

but its suppose to come out to a whole number what am i doing wrong???