Algebra 1 + 2 Flashcards
Factorising using common factors
For example, 4x* + 10xy ( * = Squared) can be factorised into 2x ( 2x + 5y ) as 2x is in both 4x* and 10xy
Factorising using Quadratics
For example, x* + 4x - 32 can be factorised to ( x + 8 )( x - 4 ) using reversed foil ( Horseshoe ). If - is at the end, the order of + or minus is + -, if + is at the end, whatever is at the start, wether it is + or -, it will be 2 of that symbol. For example if it is x* - 11x + 18 is factorised to ( x - 2 )( x - 9 ).
Factorising with Harder Quadratics
For example, 3x* - 17x + 10 is factorised to ( x - 5 )(3x-2). As there is a 3x, it may be hard to piece together the right order of the x and + numbers so keep trying until something fits!
Factorising using D.O.T.S ( Difference Of Two Squares )
If you get a question like x* - 64, you are supposed to factorise both numbers to their square roots. For example 4x* - 25 can be factorised to ( 2x + 5 )( 2x - 5 ).
Simplifying algebraic expressions
For example, 2y - 3x + 5 + 5y + 2x +1 can be factorised to the equation 7y - x + 6 by adding the X’s together and adding the Y’s together. Once this is done just add the other numbers together and you should be done!
Expanding Brackets
For Example, 2 ( 2x - 1) can be expanded to 4x - 2 if you times 2x and 1 by 2 as it is on the outside of the bracket. Another example is: 5 - 2 ( x + 9 ) can be expanded to -2x - 13
Using F.O.I.L (Firsts, Outers, Inners, Lasts)
For Example, ( 2x + 1 )( 3x - 5 ) can be expanded to 6x* - 7x - 5 by multiplying the firsts together , multiplying the outers together, multiplying the inners together and multiplying the lasts together. Once that is done add the outers and inners together and there you go!
Algebraic Identities
For Example, If ax* + bx + c = ( 5x + 1 ), we can find A, B & C by comparing the 2 sides. In this example, A = 25, B = 10 & C = 1. We can find this out by expanding ( 5x + 1 ) to 25x* + 10x + 1 which leaves you with ax* + bx + c = 25x* + 10x + 1. You then compare them and realise that ax* must be 25x* and that bx must be 10x resulting in A = 25, B = 10 & C = 1
Solving Linear Equations
For Example, 3w + 6 - w = 1 + w can be simplified to the equation 2w + 6 = 1 + w. You then swap around the 6 and w to get 2w - w = 1 - 6 which leaves you with w = -5