Presentation on theme: "A1 Algebraic expressions"— Presentation transcript:
1A1 Algebraic expressions KS3 MathematicsThe aim of this unit is to teach pupils to:Use letter symbols and distinguish their different roles in algebraKnow that algebraic operations follow the same conventions and order as arithmetic operations; use index notation and the index lawsSimplify or transform algebraic expressionsMaterial in this unit is linked to the Key Stage 3 Framework supplement of examples ppA1 Algebraic expressions
3Factorizing expressions Some expressions can be simplified by dividing each term by a common factor and writing the expression using brackets.For example, in the expression5x + 10the terms 5x and 10 have a common factor, 5.We can write the 5 outside of a set of brackets and mentally divide 5x + 10 by 5.We can write the 5 outside of a set of brackets(5x + 10) ÷ 5 = x + 2This is written inside the bracket.5(x + 2)5(x + 2)
4Factorizing expressions Writing 5x + 10 as 5(x + 2) is called factorizing the expression.Factorize 6a + 8Factorize 12 – 9nThe highest common factor of 6a and 8 isThe highest common factor of 12 and 9n is2.3.(6a + 8) ÷ 2 =3a + 4(12 – 9n) ÷ 3 =4 – 3n6a + 8 =2(3a + 4)12 – 9n =3(4 – 3n)
5Factorizing expressions Writing 5x + 10 as 5(x + 2) is called factorizing the expression.Factorize 3x + x2Factorize 2p + 6p2 – 4p3The highest common factor of 3x and x2 isThe highest common factor of 2p, 6p2 and 4p3 isx.2p.(2p + 6p2 – 4p3) ÷ 2p=(3x + x2) ÷ x =3 + x1 + 3p – 2p23x + x2 =x(3 + x)2p + 6p2 – 4p3=2p(1 + 3p – 2p2)
6Algebraic multiplication square Complete this activity as a group exercise.Use factorization to find the values of the missing terms across the top and along the side.Ask pupils how some of the multiplications could be written using brackets.
7Pelmanism: Equivalent expressions Work as a class to match equivalent expressions.