# GCSE Mathematics Sequences & Rearranging Formula -- Units 2&3

Once again the first sheet explains the topics, the second giving you questions to practice, and the third providing you with the answers.

I've included one extra question in the sequences section, if you can't work this out feel free to message me but I've been informed it's unlikely to turn up in tests.

Also you can use a calculator for these questions because they appear in both Units 2 **and** 3, however if possible try doing the first couple without.

I hope this helps, have fun revising (:

- Created by: Charley
- Created on: 05-04-12 14:01

First 460 words of the document:

Maths Revision & Help Session

Changing the Subject of a Formula

For

mul

as

are

w r

it

ten

so

that

a

singl

e var

iabl

e

the

subject

of

the

for

mul

a

is

on

the

l

eft

hand

s i

de of

t

he equat

ion.

Ever

ythi

ng el

se

goes

o n

the

ri

ght

ha nd

side

of

the

equat

ion

.

You have t

o r

everse

the

operat

ion

used so +

changes t

o

changes

to

+

x changes

to ÷

÷ changes

to x

2

changes

to

3

changes

to

³

Expandi

ng changes

to Fact

ori

sing

Fact

ori

si

n g

changes t

o Expanding

e.g. Make x the subject: y = x + 3

The subject is written on the left

So we switch the sides to get x on the left

x+3=y

The inverse of addition is subtraction.

You need to subtract 3 from the left side. But, to

keep the equality true, we need to subtract 3

from the right side as well.

So subtract 3 from both sides.

x+3-3=y-3

Simplify

x = y - 3

Sequences (nth term)

The '

nth'

t

erm i

s a

for

mu l

a wi

th

'n'

in

it

whi

ch enabl

es you

to

fi

nd

any

ter

m of

a

sequence

w i

thout

havi

ng t

o go

up f

rom one

ter

m to

the

next.

'

n'

stands

for

t

he term number

so

to

fi

nd

the

50t

h t

erm

w e

w oul

d j

ust

subst

it

ute

50

in

t

he f

ormula

in

place of

'

n'.

t

h

e.g. 2,

5,

8,

11,

14...

3n 1 t

he

11 t

erm

in

the

sequence

w oul

d be,

3 x 11 = 33

33 1 = 32

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