How do you express 3/(x−2)(x+1) in partial fractions.

"Express in partial fractions" in essence asks you to split up one fraction so that it equals the sum of several simpler fractions. So let A and B be constants. Then write:3/(x-2)(x+1) = A/(x-2) + B/(x+1) *Multiply each side by (x-2) and (x+1) to get 3 = A(x+1) + B(x-2)Then by setting x=-1 and then x=2, (to alternate making each of the brackets equal to 0) we are able to see A=1 and B=-1, which we can substitute back into * to get the answer.