## Step-by-step explanation

Problem to solve:

Learn how to solve definite integrals problems step by step online.

$\frac{1}{\left(x+1\right)\left(x-3\right)}=\frac{A}{x+1}+\frac{B}{x-3}$

Learn how to solve definite integrals problems step by step online. Integrate 1/((x+1)(x-3)) from 3 to 4. Rewrite the fraction \frac{1}{\left(x+1\right)\left(x-3\right)} in 2 simpler fractions using partial fraction decomposition. Find the values of the unknown coefficients. The first step is to multiply both sides of the equation by \left(x+1\right)\left(x-3\right). Multiplying polynomials. Simplifying.