Fractions
Key Concepts in Dealing with Algebraic Fractions
Simplifying Algebraic Fractions
- Simplifying algebraic fractions involves cancelling common factors in the numerator and the denominator.
- Prior to cancelling, factorise the expressions in the numerator and denominator where possible.
- For example, to simplify the fraction (2x+4)/(x+2), factorise to obtain 2*(x+2)/(x+2). Then, cancel out the common factor (x+2) to get 2.
Multiplication and Division of Algebraic Fractions
- Multiplying algebraic fractions requires multiplying the numerators together and the denominators together.
- Dividing algebraic fractions involves inverting the divisor fraction and then multiplying.
- For instance, to multiply (a/b) and (c/d), the result is (ac)/(bd).
- To divide (a/b) and (c/d), change the division to multiplication and invert the second fraction to get (a/b)(d/c) which simplifies to (ad)/(b*c).
Addition and Subtraction of Algebraic Fractions
- Adding or subtracting algebraic fractions requires a common denominator. If the fractions do not have the same denominator, they must be manipulated until they do.
- Once the denominators are the same, you simply add or subtract the numerators. The denominator remains unchanged.
- For example, (a/b) + (c/b) simplifies to (a+c)/b. If the fractions are (a/b) + (c/d) where b≠d, find a common denominator, change the fractions, and then add or subtract.
Strategies for Working with Algebraic Fractions
Zero in the Denominator
- Take note that having a zero in the denominator of a fraction is undefined in algebra. Hence, any values that make the denominator zero should be excluded from the solution.
Zero in the Numerator
- If you have zero in the numerator (but not the denominator), the entire fraction equals zero.
- Thus, simplifying may help reveal that a complex fraction actually equals zero.
Keep Practising
- Regular practise helps one understand the principles and process of working with algebraic fractions better.
- Different types of exercises should be explored, with different combinations of factors in the numerators and denominators.
Working with algebraic fractions forms a crucial part of algebraic proficiency, as they are commonly encountered in equations and problem solving in further mathematical studies.