Module 1: Using Formulae 1

XSIQ
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Algebra - The XSIQ petrol pump

The XSIQ petrol pump

We use formulae very frequently, often without even realising that we have
used a formula. Any time we buy something that requires weighing, measuring
or counting before a price can be calculated, we are using a formula. We
buy several things at a price per item, and we multiply the number of items
purchased by the price of each item, to find out the total that to be paid.
A common example of this is the total price for filling up the car with
petrol.

The cost of petrol can be calculated using the formula_ C_= _p_ x _L_
where_ p_ stands for the cost per litre of petrol in pounds, and_ L_ is the
number of litres.

Try out the XSIQ petrol pump. Try entering different prices per litre.
These often change between 70 pence per litre and