tan x 7 tan x 12 Step 2 Rewrite the polynomial in the denominator as u 7u 12 u 4u 1 u 7u 12 where A and B are to be determined U 3 Collect the terms according to the power of u on the right side and factorize u 7u 12 u u 4 3 u 4 u 4 u 3 Because u 7u 12 u 4 u 3 you should include one partial fraction for each factor and write B A U 4 1 U 4 Rey 3 u 12 U Step 3 Multiplying this equation by the least common denominator u u 3 yields the basic equation 3 B u 4 7 7 u 12