Idea
1/[(x+1)(x+2)] = A/(x+1) + B/(x+2)
Find A and B by matching numerators after combining the right-hand side.
Example
1/[(x+1)(x+2)] = 1/(x+1) − 1/(x+2)
FAQs
When do I use partial fractions?
They are especially useful in integration, solving equations, and simplifying rational functions.
Does this only work for linear factors?
For common algebraic uses, the method is usually applied to linear or irreducible quadratic factors.