How do you expand brackets?
Take the expression(x+2)(x+4). Expanding brackets essentially means multiplying them out to get a new expression. In this case, it will have the form x2+cx+d, where c and d are numbers to be determined. This is a rule when expending an brackets of this form- (x+a)(x+b) . Now lets now consider (x+2)(x+4). In order to correctly multiply them out, we use the expression FOIL (first, outside, inside, last). This gives us the order of multiplying. Firstly, we multiply the x's to give x2. We then move on to outside the brackets- x multiplied by 4- to give 4x. Inside will give "x multiplied by 2" to give 2x, and lastly last will give "2 multiplied by 4" to give 8. We then add all these terms together to give x2+4x+2x+8, which simplifies to x2+6x+8. This answer is now in the form x2+cx+d.
