In this worksheet, you must multiply out two algebraic brackets.
Method
When we multiply out brackets we split the first bracket and multiply each term by the second bracket, as follows:
(a + b)(c) = a(c) + b(c)
(a - b)(c) = a(c) - b(c)
(Remember - when we write a(c), we could also write this as a x (c)
So that's with one value in the second bracket, but what if we had two?
1) (a + b)(c + d) = a(c + d) + b(c + d)
= ac + ad + bc + bd
Now we have the basics we're going to apply this to some more complex maths. Remember, the process is exactly the same, even if it looks a bit more intimidating.
Examples
(x + 3)(x - 6) = x(x - 6) + 3(x - 6) = x2 - 6x + 3x - 18
= x2 - 3x - 18
(2x - 1)2 = (2x - 1)(2x - 1) = 2x(2x - 1) - 1(2x - 1) = 4x2 - 2x - 2x + 1
= 4x2 - 4x + 1