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.