x^3 - 16x over x^2-3x-10 plus x^2-9 over x^2 -4 .

Answer 1

You need to factorize each expression and cancel common factors.
Use
(x²-y²)=(x+y)(x-y) in many of the cases.

x³-16x
=x(x²-16)
=x(x²-4²)
=x(x+4)(x-4)

x²-3x-10
=(x+2)(x-5)

x²-9
=(x²-3²)
=?

x²-4
=(x²-2²)
=?