Answer: C) Find the factors of c that add up to b.
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Explanation:
If we want to factor something in the form x^2+bx+c, then we look for two numbers that
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Let's look at a specific example
Consider factoring x^2+5x+6
We need to find two numbers that...
- Multiply to c = 6
- Add to b = 5
Through trial and error, you should find the two numbers to be 3 and 2. This means it factors to (x+3)(x+2). The order of the factors doesn't matter.
You can use the FOIL rule or the box method to expand out (x+3)(x+2). You should get x^2+5x+6 again.
To factor both numerator and denominator in this rational expression we are going to substitute

with

; so

and

. This way we can rewrite the expression as follows:

Now we have two much easier to factor expressions of the form

. For the numerator we need to find two numbers whose product is

(30) and its sum

(-11); those numbers are -5 and -6.

and

.
Similarly, for the denominator those numbers are -2 and -5.

and

. Now we can factor both numerator and denominator:

Notice that we have

in both numerator and denominator, so we can cancel those out:

But remember than

, so lets replace that to get back to our original variable:

Last but not least, the denominator of rational expression can't be zero, so the only restriction in the variable is


Answer:c
Step-by-step explanation: