Question

The excluded values of a rational expression are 2 and 5. Which of the following could be this expression?

x2 - 7x+10
X+5
x2 + 7x+ 10
X+5
X+5
x2 + 7x+10
X+5
x2 - 7x+10

Answer 1

It's the last choice: (x + 5) / (x^2 - 7x + 10).

Explanation:

x^2 - 7x + 10

= (x - 5)(x - 2)

If these are a denominator of a rational expression then 2 and 5 will be excluded values.

This is because x = 5 or x = 2 makes the denominator = zero and the function then becomes undefined.

So the answer is (x + 5) / (x^2 - 7x + 10).