ADD please

Here's an easy way to do this

Multiply the numerators of both fractions by the denominators of the other fraction and add the results...so we have

2(a +b)  + 1(a-b)  =   2a + 2b + a - b  =  3a +b.....now, put this result over the product of the denominators.....so we have

(3a + b) / [(a+b)(a-b)] =   (3a + b) / (a² - b²)

And that's it.......

You can multiply the two denominators together to get a common denominator:  (a - b)*(a + b).

Multilply the first term by  (a + b) / (a + b)  and multiply the second term by  (a - b) / (a - b):

[ 2 / (a - b) ] * [ (a + b) / (a + b) ]  =  (2a + 2b) / [ (a + b) / (a - b) ]

[ 1 / (a + b) ] * [ (a - b) / (a - b) ]  =  (a - b) / [ (a + b) / (a - b) ]

Now, add the two numerators:  (2a + 2b) + (a - b)  =  (3a + b)

Writing this over the common denominator, the answer is:          (3a + b) /[ (a + b) / (a - b) ]