When we have a very complicated fraction, we can expand this fraction into a sum of multiple, simpler fractions. This uses the Linearity property of the integral to break up this extreme or impossible integral into a bunch of easier-to-solve or possible-to-solve integrals The workflow for a PFE is factoring the denominator, splitting the numerator into an equation of form A+Ax+B+Bx, with x being the variable and then solving the resulting system to find values of A and B, substituting and integrating the result.