It looks like you're saying
[tex]f(x) = ax^2 + bx + c[/tex]
and you're asked to find [tex]a,b,c[/tex] given [tex]f(0)=-4[/tex], [tex]f(1)=-1[/tex], and [tex]f(-1)=-5[/tex].
Evaluate [tex]f[/tex] at the three given points:
[tex]x=0 \implies f(0) = \boxed{c = -4}[/tex]
[tex]x=1 \implies f(1) = -1 = a + b + c \implies a+b = 3[/tex]
[tex]x=-1 \implies f(-1) = -5 = a - b + c \implies a - b = -1[/tex]
[tex](a+b) + (a-b) = 3 + (-1) \implies 2a = 2 \implies \boxed{a=2}[/tex]
[tex]a-b = -1 \implies \boxed{b=3}[/tex]
and the mapping is [tex]f(x) = 2x^2 + 3x - 4[/tex].