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Jun 272014

A jigsaw to revise linear graphs and their equations. Do you remember y=mx+c? m is the gradient, c is the intercept on the y axis. If you have forgotten this look here first.

Some of these equations need re-arranging so you can find the gradient and intercept, but others are already in the y=mx+c format.

I think this is one of the best jokes yet! Do you get it?

Feb 022014

Do you understand the difference between a formula, expression, identity and equation?

A formula is a rule written using symbols that describe a relationship between different quantities. Typical maths formulae include

A = πr² (area of a circle)

C=πd (circumference of a circle)

An expression is a group of mathematical symbols representing a number or quantity. Expressions never have equality or inequality signs like =, >, <, ≠ ,≥ ,≤. Some examples


3xy + 4x

t² + t³

An identity is an equation that is always true, no matter what values are chosen.


3a + 2a =  5a

x²+x² = 2x²

5 x 10 = 10 x 5

An equation is a mathematical statement that shows that two expressions are equal. It always includes an equals sign.


x² =100

3x(x+5)= 42


Use this exercise to make sure you understand the difference.

Jan 122014

In the last exercise you learnt how to factorise quadratic expressions. We will now use this in order to solve simple quadratic equations.

Suppose x²+9x +20 = 0

If we factorise we get (x+4) (x+5) = 0

In other words, two numbers multiply together to make 0. This means one of those numbers must be 0!

So we know EITHER x+4 = 0 OR x+5 = 0

If x +4 = 0 x = -4

If x+5 =0 then x=-5

So the solution is x = -4 or -5

Remember quadratic equations will nearly always have 2 solutions.

Try this- you will probably need pencil and paper to factorise the equations first.