Question

For the function f(x) = x2 + 2x - 15 solve the following.f(x) = 0Select the correct choice below and fill in the answer box within your choice.O A. The solution is { }(Use a comma to separate answers as needed.)B. The solution is(Type your answer in interval notation.)

Answer 1

Answer: A. The solution is {-5,3}

Given:

$\begin{gathered} f(x)=x^2+2x-15 \\ f(x)=0 \end{gathered}$

Let us solve for x when f(x)=0

$\begin{gathered} f(x)=x^2+2x-15 \\ 0=x^2+2x-15 \end{gathered}$

Factor the quadratic equation:

$\begin{gathered} 0=x^2+2x-15 \\ 0=(x+5)(x-3) \end{gathered}$

Solve for x:

$\begin{gathered} 0=(x+5)(x-3) \\ ------------ \\ x+5=0 \\ x=-5 \\ ------------ \\ x-3=0 \\ x=3 \end{gathered}$

Therefore, the solution is {-5,3}