Finding Common Demoninators in fractions.

1)
2 4
-- - ---
x^2-16 x^2+x-12

2)
x-3 x+3
---- + ------
x^2+2x-8 x^2+7x+12

Can ANYONE help me with these.
I cant figure out how to get the DEMONINATORS THE SAME!?

Use brackets to write these kind of fractions, the text editor of this board does not seem to recognize more than one space.

Your first denominator is x^2-16, which factors to (x+4)(x-4)

The second denominator is x^2 + x - 12
which factors to (x+4)(x-3)

So the lowest common denominator is
((x+4)(x-4)(x-3)

So multipy the first fraction by (x-3)/(x-3)
and the second by (x-4)/(x-4)

Do the same thing for the second, factor the bottoms and your LCD must contain all of the factors.

Let me know if you got it.

1 answer

cool brah