A few days ago
boooo.

Someone explain this to me? adding the fractions and then simplifying..?

So, I know I’ve learned this before and I’m generally good at math, but I forgot how to do this!

I have to add the two fractions and then simplify.

(x / x -1) + (x + 1 / 3x – 4)

The back of my textbook says that the answer is 4x^2 – 4x -1 / (x -1) (3x – 4)

But, what do I do to get to that answer?

Sorry, if it’s hard to read..

Top 2 Answers
A few days ago
sayamiam

Favorite Answer

to add fractions, they need to have common denominators:

so multiply by (3x-4)(x-1)/(3x-4)(x-1)

the first fraction becomes:

(3x^2-4x)/(3x-4)(x-1)

the second fraction becomes:

(x^2-1)/(3x-4)(x-1)

add them to get:

(4x^2-4x-1)/(3x-4)(x-1)

And if you had trouble, you could have started off by trying to make both fractions resemble the answer in the back of the book i.e. the denominators.

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A few days ago
Betsy D
You must give the fractions the same denominator. Notice how in the answer, the denominator is (x-1)(3x-4).

In order to do this, multiply (x/x-1) by (3x-4/3x-4).

Also multiply (x+1/3x-4) by (x-1/x-1).

Notice that (3x-4/3x-4) and (x-1/x-1) both equal 1 (they are divided by themselves). So when you multiply the fractions by these new fractions, you are multiplying by 1.

I’ll start the first part for you.

(x/x-1)*(3x-4/3x-4) = (3x^2 – 4x / (x-1)(3x-4))

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