Question

if f(b) = -3b^ -5b -5 find the value of f(2b) + f(-b) ​

Answer 1

Answer:

Given, f(x)=ax

2

+bx+c,f(−1)=−18,f(1)=10

f(−1)=a−b+c=−18 and f(1)=a+b+c=10

Now subtract above two equations, we get

2b=28

⇒b=14

I hope this helps you