Tiêu đề MATHS PART -1.pdf ✅

(a + b) 2 = a 2 + 2ab + b 2 (a − b) 2 = a 2 − 2ab + b 2 (a + b)(a − b) = a 2 − b 2 The general form of the three standard identities is (x + a)(x + b) = x 2 + (a + b)x + ab. An algebraic expression can be written as a product of its factors. The fators may be constants variables or algebraic expressions. A facrors of an expressions is said to be irreducible if it can be further expressed as a product of factors. Algebraic expressions can be factorised by taking common factors, by regrouping by rewritting the middle term or by using any one of the following identities. a 2 + 2ab + b 2 = (a + b) 2 = (a + b)(a + b) a 2 − 2ab + b 2 = (a − b) 2 = (a − b)(a − b) a 2 − b 2 = (a + b)(a − b) x 2 + (a + b)x + ab = (x + a)(x + b) If the given expression is in the form of the LHS of these identities, the factors are in the form of the RHS of these identities and vice versa. A polynomial can be divided by a monomial either by taking common factors and cancelling or by dividing each term of the polynomial by the monomial and adding the quotients. Division of a polynomial by a polynomial can be done by a) Factorising the polynomials which s possible only if the divisor is a factor of the dividend. b) By the long division method, which can be used even when the divisor is not a factor of the dividened. The long divison method can be used to find out whether or not the given