Rational Expressions with Unlike Denominators (Jump to: Lecture | Video )

Rational Expressions

A Rational Expression is an algebraic fraction which has polynomials in both the numerator and denominator.

Rational Expressions can be added and subtracted just like regular fractions.

Unlike Denominators

Fractions with different values in their denominators have unlike denominators.

To make the denominators equal, we need to find their Least Common Multiple(LCM).

Figure 1.

First, we need to find the LCM of the two fractions above:

Figure 2.

Now we need to make both fractions have "2x" in their denominator, then we can subtract them:

Figure 3.

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