Teaching and Learning Activities Example 6: Dividing three expressions \[ \begin{aligned} 12 a^{2} b \div 2 a \div(-3 b) & =-\frac{12 a^{2} b}{2 a \times 3 b} \\ & =-2 \mathrm{a} \end{aligned} \] \[ \begin{aligned} A \div B \div C & =\frac{A}{B} \div C \\ & =\frac{A}{B \times C} \end{aligned} \] Key Ideas Multiply monomial expressions by taking the product of the coefficient and multiplying it by the product of the letters. Exercises 32 1. Calculate. (i) \( (-4 x) \times 5 y \) (ii) \( (-7 y) \times(-3 x) \) (iii) \( \frac{5}{9} a \times(-3 b) \) (iv) \( \frac{1}{2} x \times \frac{3}{4} x \) 2. Calculate. (i) \( (-7 a)^{2} \) (ii) \( \frac{1}{3} x \times(3 x)^{2} \) (iii) \( -(4 x)^{2} \) (iv) \( (-a)^{2} \times 3 a \) 3. Calculate. (i) \( (-6 a b) \div 2 a \) (ii) \( 8 x^{2} \div x \) (iii) \( \left(-9 x^{2} y\right) \div(-3 y) \) (iv) \( 5 a^{2} \div\left(-10 a^{2}\right) \) 4. Calculate. (i) \( 7 x^{2} \div\left(-\frac{7}{4} x\right) \) (ii) \( -\frac{5}{18} a b \div\left(-\frac{10}{9} b\right) \) (iii) \( -\frac{1}{5} x^{2} y \div \frac{1}{5} x \) (iv) \( \frac{2}{3} y^{2} \div \frac{3}{2} y^{2} \) 5. Calculate. (i) \( 2 a \times 3 a b \times 4 b \) (ii) \( 6 a b \times(-7 a) \div 14 b \) (iii) \( 8 x^{2} \div(-4 x) \times(-3 x) \) (iv) \( 16 x y^{2} \div 4 y \div(-2 x) \)