You need to focus on two chapters to understand how to simplify rational expressions.
The first chapter contains the addition/subtraction of rational expressions that do not have a common denominator.
Since you will understand better an worked example, you may consider the following example such that:
`1/(x-1) + (2x-5)/(x+1)`
Notice that the fractions do not have a common denominator, hence, you will need to identify the common denominator. In this case, since the denominators do not share a common factor, the common denominator will be the following product, such that:
`(x+1)(x-1) = x^2- 1`
You need to identify what is the missing factor to the first denominator and to multiply the fraction by the value identified, such that:
`1*(x+1)/((x-1)(x+1)) + ((2x-5)(x-1))/((x-1)(x+1)) `
Since the fractions share the same denominator, you may write the expression such taht:
`(x + 1 + (2x - 5)(x - 1))/(x^2 - 1)`
You need to open the brackets such that:
`(x + 1 + 2x^2 - 2x - 5x + 5)/(x^2 - 1) = (2x^2 - 6x + 6)/(x^2-1)`
Factoring out 2 to numerator yields:
`(2x^2 - 6x + 6)/(x^2-1) = 2(x^2 - 3x + 3)/(x^2-1)`
Hence, simplifying the expression yields `1/(x-1) + (2x-5)/(x+1) = 2(x^2 - 3x + 3)/(x^2-1).`
The first chapter contains the multiplication or division of rational expressions.
Selecting the following example yields:
You need to identify if there exists duplicate factors to numerator and denominators and cancel the factors, such that:
`1/(x+1)*(x-1)/1` ( notice that `5x-1` is the duplicate factor)
Hence, simplifying the expression yields `(5x-1)/(x+1)*(x-1)/(5x-1) = (x-1)/(x+1).`