Question

Quiz

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A function f(x) has x-intercepts of -3 and -5. What is the
f(x) = x2 + 8x +​

Answer 1

`f(x)=x^2+8x+15`

Explanation:

If the function f(x) has x-intercepts of -3 and -5 then the roots are
`x=-3` and
`x=-5`.

The factors of this function are
`x+3` and
`x+5`.

We can write the function in factored form as:

`f(x)=(x+3)(x+5)`

We expand using the distributive property to get:

`f(x)=x^2+5x+3x+15`

`f(x)=x^2+8x+15`