If you’ve started algebra, you’ve probably heard a few new words being used which might be confusing you:
Expression – These are a bit like algebra sums, but there is no equals sign. So you don’t need to solve an expression, but usually they need simplifying, which we’ll look at in this post.
Algebraic Formula: This tells you how to do a calculation to work something out. For example, let’s say I want to order pizza for dinner and one pizza costs £12. If I want 2 pizzas, the cost will be 2 lots of £12, 3 pizzas is 3 lots of £12 and so on. We could write a very basic formula for working out the cost of pizzas.
Cost could be c and number of pizzas could be p. So our formula would be:
If there was a delivery charge, say £3 the formula would be:
c = 12p +3
An equation is similar to an algebraic formula and these are the ones you have to solve. E.g.
\[x^2\ +\ 5x\ +\ 6\ =\ 0\]
We looked at solving equations in a previous post here.
When a question asks you to simplify an expression, it means it wants you to round up all the letters that are the same and rewrite it.
For example, if we have the sum:
2 + 2 + 2 + 2 + 2
It would be faster and simpler to write 5 x 2.
It’s the same with algebra.
\[x+x+x+x+x\ =\ 5x\]