Wednesday, 16 July 2014

Fractions

Classification of Fractions

  1. Proper Fraction :

    A Proper Fraction is one whose numerator is less than its denominator. eg: 1/4, 5/8
  2. Improper Fraction :

    An Improper Fraction is one whose numerator is equal to or greater than its denominator. eg: 6/4, 5/5
  3. Mixed Fraction :

    A Mixed fraction is a quantity consisting of two parts, one a whole number and other a proper fraction. eg: 31/8, 83/5 A Mixed Fraction can always be expressed as an improper fraction.

Tuesday, 15 July 2014

Simplification

 

VBODMAS

'VBODMAS' (Vinculum - Bracket - Of - Division - Multiplication - Addition - Subtraction) rule should be applied for solving problems involving one or more mathematical operations like multiplication, division, addition, subtraction etc.such problems are solved i n the order of vinculum, bracket, of, division, multiplication, addition, subtraction.

Simplification Using Identities

  1. a x (b x c) = a x b + a x c
  2. (a + b)2 = a2 + 2ab + b2
  3. (a - b)2 = a2 - 2ab + b2
  4. (a + b)2 = (a - b)2 + 4ab
  5. (a - b)2 = (a + b)2 + 4ab 
  6. (a - b) (a + b) = a2 - b2 
  7. (a + b)3 = a3 + 3ab (a + b) + b3 
  8. (a - b)3 = a3 - 3ab (a - b) - b3 
  9. a3 + b3 = (a + b) (a2 - ab + b2)
  10. a3 - b3 = (a - b) (a2 + ab + b2)
  11. a3 - b3 / a2 + ab + b2 = a - b 
  12. a3 + b3 / a2 - ab + b2 = a + b 
  13. a2 - ab + b2 / a3 + b3 = 1 / a + b 
  14. a2 + ab + b2 / a3 - b3 = 1 / a - b
  15. (a + b)2 + (a - b)2 = 2 (a2 + b2)
  16. (a + b)2 - (a - b)2 = 4ab

Basic Arithmetic Operations

 

Addition

  1. Positive no + Positive no = Positive no , Eg: 6 + 5 = 11
  2. Negative no + Negative no = Negative no , Eg: -4 + -7 = -11
  3. Negative no = Positive no = Difference of the nos and sign of greater no , Eg: +8 + -10 = -2

Multiplication

  1. Positive no x Positive no = Positive no , 6 x 3 =18
  2. Negative no x Negative no  = Positive no , -2 x -6 = 12
  3. Positive no  x Negative no = Negative no , 5 x -6 = -30
  4. Negative no  x Positive no = Negative no , -8 x 2 = -16

Division

  1. Positive no ÷ Positive no = Positive no , 18 ÷ 3 = 6
  2. Negative no ÷ Negative no  = Positive no , -12 ÷ -6 = 2
  3. Positive no  ÷ Negative no = Negative no , 30 ÷ -6 = -5
  4. Negative no  ÷ Positive no = Negative no , -16 ÷ 2 = -8