ok your denominators have to be exactly the same, then you just add or subtract straight across the top part, the numerator
what i would do first is factor out your denominators
then multiply so that your denominators have the same binomials
1 3/x5 + 7/5x
3 + 7
x5 5x
3 (5x) + 7(x5)
(x5)(5x) (x5)(5x) <I took the denominator from the left and multiplied it, top and bottom, on the right. I did the same thing with the other side, take the denominator from the right and multiply it top and bottom on the left.
15  3x + 7x35
5x  x^{2} 25+5x 5x  x2 25+5x <foil the denominators, combine terms next
15  3x + 7x35
x^{2}+10x 25 x2+10x 25 < once everything is cleaned up, you have to add the numerators, when you add, the fractions will combine into one. dont do anything with the denominators when you add or subtract
15  3x + 7x35
x2+10x 25 < combine terms again
4x + 20
x2+10x 25
10/6/2013

Justin L.