Use factorisation to simplify the following expression (x^2-9)/(x^2-4x+3)

we simplify the top and bottom of the fraction separately. x^2-9 factorises to (x+3)(x-3) using the difference of two squares.x^2-4x+3 factorises to (x-1)(x-3). So the above formula simplifies to (x+3)/(x-1)