How to solve simultaneous linear equations.. using algebra…
These videos show how to solve simultaneous linear equations in steps.
- The first video should be relatively straightforward as it only deals with positive numbers.
- The second is a little trickier (around level B) and involves dealing with a negative term.
- The third video … shows more of a real application..
Learning how to solve simultaneous linear equations can be important for applications in economics, such as working out the best price to sell a product. This is usually called ‘supply and demand.’
Imagine you make pencils:
- If you sell at a high price they’ll be less demand
- If you sell at a low price they’ll be too many and less profit
Simultaneous equations can be created to show how quantities sold vary with supply and demand. These can then be solved to show the best price to make sure you sell your pencils, and the demand continues.
Another example – a favourite in exams – is to use mobile phone contracts. Sometimes these are given as a graph and there’s more about this in the next post. Although the question is usually two linear equations, and it asks you to pick the best value.
One of my favourite exam questions involves The Khans and The Smiths buying theatre tickets. Each family has got different numbers of adults and children … and you need to create a couple of simultaneous equations to work out the price of each ticket.
These kind of questions may be a little strange (why didn’t they just ring the box office?), but they do give an insight into how equations work. There are other examples such as arranging a meeting half way through a journey or working out the cost of bank loans.
Please add a comment below with any more real life examples.
Watch the videos on YouTube: