1. Using Formulae
By the end of the lesson, you should have a good understanding of:
The usefulness of formulae
How to produce a formula
How to rearrange formulae to suit a situation

2. (where c is the cost in £ and d is the distance in miles)
Taxi Fare
A taxi-driver charges a fixed rate of £2 per journey plus 50p per mile.
How much does it cost to travel 10 miles?
£2 + £0.50 x 10 = £7
Can you produce a formula for the cost of travel?
c = d
(where c is the cost in £ and d is the distance in miles)

3. (where c is the cost in £ and d is the distance in miles)
Taxi Fare
A taxi-driver charges a fixed rate of £2 per journey plus 50p per mile.
How far can you travel for £10?
(£10 - £2) / £0.50 = 16 miles
Can you produce a formula for the cost of travel?
d = (c - 2) / 0.5
or: d = 2(c – 2)
(where c is the cost in £ and d is the distance in miles)

4. Taxi Fare
A taxi-driver charges a fixed rate of £2 per journey plus 50p per mile.
c = d .
c – 2 = d
2(c – 2)= d #
Changing the subject

9. 1) 2) 3) 4)
a=, b=, c=
m1=, m2=, r=
v=, u=, a=, s=
u=, a=, t=

14. ms-2 ms-1 ms-1 m m2s-2 m2s-2 ms-2m
In a formula, the dimension of the sides is always the same

15. 1 m s
ms-2
_m_
ms-2 s

16. m s
ms-2
ms-1 s