# Formulas + Brain Frames

Has everything for Module 5 of the June exam

- Created by: elliott miller
- Created on: 10-04-11 13:29

First 215 words of the document:

Formulas and Methods for AQA Module 5/Unit 3, Grades E, D and C.

Algebra

Negative Numbers

Adding/Subtracting Multiplying Dividing

5++3=8 In brief +×+=+ +÷+=+

5+-3=2 ++ = + +×-=- +÷ -=-

5-+3=2 +- = - -×+=- -÷ +=-

5--3=8 -+ = - -×-=+ -÷ -=+

If you subtract a

-- = +

negative number If you multiply or divide two negative

you add. numbers the answer is positive

Powers and roots

x 2 = x × x E.g. 52 = 5 × 5 = 25 x3 = x × x × x E.g. 23 = 2 × 2 × 2 = 8

Square root: 64 = 8 or - 8 Cube root: 3 27 = 3

Because 8 × 8 = 64 and -8 × -8 = 64 Because 3 × 3 × 3 = 27

Substitution into formulas

Replace the letters by the numbers given and workout:

E.g. Find 4x + 3y when x=5, y=-7

4x + 3y Remember 4x means 4×x

= 4 × 5 + 3 × -7

=20 21

=-1

Linear Equations

Move all the x-terms to one side, all the numbers to the other. Remember if you move a term from one

side of the = to the other you have to change the sign. (This is the effect of doing the same to both

sides).

E.g. E.g.

4x + 7 = 3 3 y - 11 = 9 - y

4x = 3-7 3 y + y = 9 + 11

4x = -4 4 y = 20

x= -1 y=5

gdw

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