Ok... so this question can be solved by using simultaneous equations.
Use the general from of a parabola
you know the value of c, the y-intercept... y = -4
which means the equation is
now use the other 2 points to get 2 equations in 2 unknowns
(-2, -20) just substitute
this becomes
now the other equation using (4, -20)
The simplified form is
Use the general from of a parabola
you know the value of c, the y-intercept... y = -4
which means the equation is
now use the other 2 points to get 2 equations in 2 unknowns
(-2, -20) just substitute
this becomes
now the other equation using (4, -20)
The simplified form is