GCSE Maths

Algebra page

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Definitions

Expression: any arrangement of: letter symbols; numbers; +, -, x and ÷ signs; powers; and brackets. eg 2a(8b2-4cq)

Equation: A statement asserting the equality of two expressions, containing symbols that are separated into left and right sides and joined by an equal sign. eg 2p + 3q = 49

Formula: An equation that desribes a rule concerning the real-life behaviour of something. eg Boyles Law in Physics PV = k

Identity: A connection between expressions that remains true whatever the values of the letter symbols.

Function: a relationship between two sets of values such that a value from the first set maps on to a unique value in the second set.

Shorthand way of writing down a multiplication in algebraic expressions: eg m x n can be written as mn and ap x aq can be written as apaq. ie. the times sign (x) can be left out.

Index Laws

Multiplication and division ap x aq = ap+q
  ap ÷ aq = ap-q
Brackets (ap)q = apxq
Zero index a0 = 1 (and remember a1 = a)
Reciprocal index 1/ap = a-p

Note: ap + aq does NOT equal ap+q. It can’t be simplified any more.


Problems to solve:

Simplify:

Square root of a8
Square root of a2b4
80
(85)0
(x5)0
(x3y7)0
41
(x5)1
(55)1
(x3y7)
(6-4) ÷ (6-2)
(x-4) ÷ (x-2)
(9-374) ÷ (9-272)
(x-3y4) ÷ (x-2y2)