Page 47 - Year 9 Knowledge Organiser
P. 47

Maths: Quadratics(set 1 and 2 only): 2 of 8  Maths: Inequalities, equations and formulae (set 1 and 2 only): 3 of 8


                                                                     Inequalities on a number line
 Basic Algebra   Expanding
 Substitution   Expanding Single Brackets  Solving linear inequalities
                                                                                                                              Key Concepts
 When we substitute values into a
 Algebraic Indices  Expanding double brackets that
 Simplify   formula we take out the variables   look like single brackets                                         Solving equations:
 and put in the numbers.
 You must use the rules of indices when simplifying                                                               Working with inverse operations to find
 with algebra
 Example: 2a + 4b                                                                                                 the value of a variable.
 Where a = -3 and b = 5
                                                                                                                  Rearranging an equation:
 You do 2 x –3 = -6                                                                                               Working with inverse operations to
 And 4 x 5 = 20  Expanding double brackets
 Solving Equations                                                                                                isolate a highlighted variable.
 Then add them together:  REARRANGE AND SOLVE EQUATIONS
 -6 + 20 = 14                                                                                                     In solving and rearranging we undo the
                                                                                                                  operations starting from the last one.
 When expanding brackets it   Solve:         Rearrange to make r             Rearrange to make c the
 is easier to use grid method.                 7p – 5 = 3p + 3  the subject of the   subject of the formulae :
 Make sure you simplify at          -3p                               -3p
                                                                                 2(3     –      ) =  5      +  1
 the end                    4p – 5 =  3      formulae :                        expand                                              Key Words
                    +5                                 +5                       =  2     −7    6     – 2      =  5      +  1  Solve – to find the solution to an equation
                                                              3
                                   4p =  8        ×3                  × 3       +2                                         +2      Rearrange – change the subject of a
 Quadratic Sequence          ÷ 2                              ÷ 2                3Q = 2     − 7     -1                                          -1  formula by using the balancing method
                                                                                     6a = 7     + 1
                                     p = 2
 Factorising Double Brackets  Factorising into a single bracket  Solve:       +7                              +7  6a − 1 = 7    
 Variables and numbers               5(x – 3) = 4(x  + 2)              3Q + 7 = 2        ÷ 7                                     ÷ 7  Term – one item in an expression,
               expand                      expand     ÷ 2                             ÷ 2  6     − 1   =                    sequence or equation
                          5x – 15 = 4x + 8                    3    + 7   =               7
                    -4x                              -4x           2                                               Inverse – to do the opposite action (for
             x – 15 =  8
                    +15                             +15                                                                example adding is the inverse of
                                    x = 23                                                                                        subtracting)
   42   43   44   45   46   47   48   49   50   51   52