Expanding brackets part three

Here is a depiction of (x + 5)^2

The sides of the outer square are x + 5. The area of the outer square represents (x + 5)^2. We can see this is made up of the red x^2 square and the two yellow 5x rectangles and the blue 5^2 square.

We can rearrange these shapes to show this more clearly. (x + 5)^2 gives x^2+ 2\times 5x + 5^2

We can generalise this. When we expand brackets that have the form (x + c)^2 where c is a constant, we get x^2 + 2cx + c^2

Going back to our example, when the constant is 5, we get (x + 5)^2 = x^2 + 2\times 5x + 5^2 = x^2 + 10x + 25

You should be able to look at similar brackets that are squared and be able to quickly see what the terms expand to.

For example (x + 3)^2 = x^2 + 6x + 3^2 = x^2 + 6x + 9

You may even get to the stage where you can look at some squared bracketed term like (x + 4)^2 and see straight away that this is the same as x^2 + 8x + 16