Review of the Grade 8 course

We close the year briefly. With algebraic fractions we first factor, bring to a common denominator and reduce; the denominator must not be zero. For rational exponents a^(m/n) = ⁿ√(aᵐ), the base is positive, and the properties are as for natural exponents. In inequalities, multiplying by a negative number reverses the sign; the solution of a system is the common part; |x| < a ⇔ -a < x < a. In a quadratic equation we compute D = b² - 4ac and find two roots if D > 0 and one if D = 0; Vieta’s theorem gives x₁ + x₂ = -p, x₁x₂ = q. In statistics we use the mean, mode, median and range, and in combinatorics the multiplication and addition rules.