**Question 1: Simplify using laws of indices**
1.i Simplify $ (b^4)^3 b^{-2} $
Step 1: Use the power of a power rule: $$ (b^4)^3 = b^{4\times3} = b^{12} $$
Step 2: Multiply by $ b^{-2} $: $$ b^{12} \times b^{-2} = b^{12-2} = b^{10} $$
1.ii Simplify $ (-3x)^2 + 3x^2 $
Step 1: Expand the square: $$ (-3x)^2 = (-3)^2 \times x^2 = 9x^2 $$
Step 2: Add: $$ 9x^2 + 3x^2 = 12x^2 $$
1.iii Simplify $$ \left(\frac{x}{y}\right)^2 x^2 y $$
Step 1: Expand the square: $$ \left(\frac{x}{y}\right)^2 = \frac{x^2}{y^2} $$
Step 2: Multiply by $ x^2 y $: $$ \frac{x^2}{y^2} \times x^2 y = \frac{x^{2+2} y}{y^2} = \frac{x^4 y}{y^2} $$
Step 3: Simplify $ y $ terms: $$ \frac{y}{y^2} = y^{-1} $$
Final answer: $$ x^4 y^{-1} = \frac{x^4}{y} $$
1.iv Simplify $$ \frac{a^{-3} b^7}{a^5 b^3} $$
Step 1: Apply laws of indices for division: $$ a^{-3-5} b^{7-3} = a^{-8} b^4 $$
Step 2: Rewrite negative exponent: $$ \frac{b^4}{a^8} $$
1.v Simplify $$ \frac{4^{20} - 4^{18}}{4^{18}} $$
Step 1: Factor numerator: $$ 4^{18} (4^2 - 1) $$
Step 2: Rewrite expression: $$ \frac{4^{18} (16-1)}{4^{18}} = 16 - 1 = 15 $$
**Question 2: Fill in the blanks with set symbols**
2.i $ a \quad \in \quad \{a, b, c, d\} $
2.ii $ \{4, 5\} \quad \subseteq \quad \{1, 2, 3, 4, 5\} $
2.iii $ \{b, c\} \quad \in \quad \{a, \{b, c\}, d\} $
2.iv $ -4 \quad \notin \quad \{1, 2, 3, 4, 5\} $
2.v $ \{1, -\frac{2}{3}\} \quad = \quad \{ x \mid 3x^2 - x - 2=0 \text{ and } x \text{ is a real number} \} $
Final answers:
1.i $b^{10}$
1.ii $12x^2$
1.iii $\frac{x^4}{y}$
1.iv $\frac{b^4}{a^8}$
1.v $15$
2.i $\in$
2.ii $\subseteq$
2.iii $\in$
2.iv $\notin$
2.v $=$
Laws Indices Set Theory
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