Question

Let f (x) = x^2 + 8x.a) Evaluate f(-3).b) Solve f(x) -16.

Answer 1

Solution

We have the following function:

$f(x)=x^2+8x$

Part a

$f(-3)=9-72=-68$

Part b

We can do this:

$x^{2}+8x+16=0$

If we factorize we got:

(x+4)²

Then the answer is:

x=-4