Formulae and

simultaneous equations

7

Contents:

A Formula substitution [2.5]

B Formula rearrangement [2.5]

C Formula derivation [2.5]

D More difficult rearrangements [2.5]

E Simultaneous equations [2.6]

F Problem solving [2.6]

Opening problem

#endboxedheading

Toby owns a fleet of trucks, and the trucks come in

two sizes. The small trucks can carry a maximum of 3

tonnes, while the large trucks can carry a maximum of

5 tonnes.

There are 25 trucks in Toby’s fleet, and the trucks can

carry a combined total of 95 tonnes.

How many trucks of each size does Toby own?

In this chapter we expand on our knowledge of algebra to consider equations with more than one unknown

or variable.

We will first considerformulaewhich describe the relationship between variables.

We will then consider pairs of equations with two variables which can be solvedsimultaneouslyto find the

values of the unknowns.

IGCSE01

cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_07\147IGCSE01_07.CDR Wednesday, 17 September 2008 10:03:39 AM PETER