1. Problem 10: Calculate the highest temperature recorded at Scott Base. The problem states the highest temperature recorded is 63.8 °C. Since the highest temperature is already given as 63.8, the answer is simply 63.8 °C. 2. Problem 11 (a): Simplify the expression $4a - 3b + 5a + 6b$. Step 1: Group like terms: $(4a + 5a) + (-3b + 6b)$. Step 2: Simplify each group: $9a + 3b$. So, the simplified expression is $9a + 3b$. 3. Problem 11 (b): Factorise the expression $4x^2y + 8x - 10xy$. Step 1: Identify common factors in each term. Step 2: The terms are $4x^2y$, $8x$, and $-10xy$. Step 3: The greatest common factor (GCF) is $2x$. Step 4: Factor out $2x$: $2x(2xy + 4 - 5y)$. This is the factorised form. Final answers: 10. Highest temperature recorded: $63.8$. 11 (a). Simplified expression: $9a + 3b$. 11 (b). Factorised expression: $2x(2xy + 4 - 5y)$.