Question

Suppose the quadratic function $f(x)=ax^{2} +bx+c$ with $f(-2)=0$ and $-\frac{b}{2a} =1$. Solve $f(x)=0$.

Answer 1

Answer:

Step-by-step explanation:

hello :

let : X1 and X2  this solution you have : X1 + X2 = -b/a

but given : -b/2a = 1   so : -b/a = 22

now :  X1 + X2 = 2

other solution is : -2  because f(-2) =0

so : -2+X2 = 2    X2 = 4

f(x) = (x-4)(x+2) = x²-2x-8      a=1   and b=- 2   and c= -8

verify : f(-2) = (-2)²-2(-2)-8=8-8=0....right

-b/2a = -(-2)/2(1) = 1 ...right

the soultions are : 4  and -2