Question

What is Multiplication of Rational Expressions?

Answer 1

Multiplication of rational expressions is actually very easy -much easier than adding rational expressions!-

In fact, if you have two rational expressions `a/b` and `c/d` the product `a/b \cdot c/d` is simply a fraction whose numerator is the product of the numerators, and whose denominator is the product of the denominators, i.e. `{ac}/{bd}`.

Note that this holds for any kind of rational expressions, not only with numbers: if you have two fractions involving functions, it will work the same: for example,
`\frac{x^2}{e^x}\cdot\frac{\cos(x)}{x^2+1}=\frac{x^2\cos(x)}{e^x(x^2+1)}`