i need help please

Answer 1

Here are some terrific sites that will explain what you need to know.

http://www.aaamath.com/

http://mathforum.org/library/drmath/drmath.elem.html

If you have specific questions, be sure to repost.

Answer 2

http://www.math.com/school/subject1/lessons/S1U4L3GL.html

http://www.themathpage.com/Arith/add-fractions-subtract-fractions-1.htm