How do I expand double brackets? E.g. (4x+7)(3x+5)
In order to expand the brackets, we need to ensure that EVERYTHING in the left bracket is multiplied by EVERYTHING in the right bracket. There are 3 methods for helping us to times out the brackets. These are: the FOIL method, the face method and the grid method.The FOIL methodFOIL is an acronym to help us to remember to multiply everything together. It stands for:FrontOutsideInsideLast1) First, we multiply the FRONT terms together (4x+7)(3x+5)With the help of pupil4x times 3x = 12x22) Next, we multiply the OUTSIDE terms together (4x+7)(3x+5) With the help of pupil4x times 5 = 20x3) Then, we multiply the INSIDE terms together (4x+7)(3x+5)With the help of pupil7 times 3x = 21x4) After, we multiply the LAST terms together (4x+7)(3x+5) With the help of pupil7 times 5 = 355) Finally, we have to add up each term to ensure that we get the whole answer 7 With the help of pupil12x2 + 20x + 21x + 35 = 12x2 + 41x + 35If the pupil seemed to understand this method then I would do another question using this method. If not, I would continue to explain the other methods to see if they were easier for the pupil to understand.
