Question

What about this one ?

Answer 1

The options are given in factored form.

If a function is zero at x=3, this means x=3 is a root of the equation. x = 3 can also be written as x - 3 = 0

So, if x = 3 is a root of the equation, x - 3 will be a factor of the function. From the given options we can see only Option C contains x - 3 as its factor. Substitute x = 3 in option C and the function value will be zero.

So, the correct answer is option C

Answer 2

We need to find 0 so what we would do is replace the x with 3 as the question is asking and solve from there. 

Let me demonstrate by using an example:

x = 4

6+x= 10

6+4=10 

In this example, I replaced the x with 4 which resulted in 10.

Now, let's solve! 

The answer is the third option because it results 0 and I will show you why! 

First, we replace the x with 3

(3+20)(3-3)

Using our knowledge of PEMDAS we would first solve what's inside the parentheses and then multiply!

3+20= 23 and 3-3=0

Now, we multiply 23*0 and we got the answer of 0 which is what the problem is asking for.

Therefore, the correct answer is the third option or (x+20)(x-3)