how to factorise example please
Answers
Answer:
Brackets should be expanded in the following ways:
For an expression of the form a(b + c), the expanded version is ab + ac, i.e., multiply the term outside the bracket by everything inside the bracket (e.g. 2x(x + 3) = 2x² + 6x [remember x × x is x²]).
For an expression of the form (a + b)(c + d), the expanded version is ac + ad + bc + bd, in other words everything in the first bracket should be multiplied by everything in the second.
Example
Expand (2x + 3)(x - 1):
Expand (2x + 3)(x - 1):(2x + 3)(x - 1)
Expand (2x + 3)(x - 1):(2x + 3)(x - 1)= 2x² - 2x + 3x - 3
Expand (2x + 3)(x - 1):(2x + 3)(x - 1)= 2x² - 2x + 3x - 3= 2x² + x - 3
Factorising
Factorising is the reverse of expanding brackets, so it is, for example, putting 2x² + x - 3 into the form (2x + 3)(x - 1). This is an important way of solving quadratic equations.
The first step of factorising an expression is to 'take out' any common factors which the terms have.
So if you were asked to factorise x² + x, since x goes into both terms, you would write x(x + 1) .