Question: 1. Simplify the expression 6x - (6 - 24x) + 10.
2. Simplify the expression 4xy + (24x - 13y) - 12 + 3yx - 5y.
3. A firm produces two goods, X and Y, which it sells at prices per unit of £26 and £22 respectively. Good X requires an initial outlay of £400 and then an expenditure of £16 on labour and £4 on raw materials for each unit produced. Good Y requires a fixed outlay of £250 plus £14 labour and £3 of raw material for each unit. If the quantities produced of X and Y are x and y, respectively, write an expression in terms of x and y for the firm's total profit and then simplify it.
4. A worker earns £6 per hour for the first 40 hours a week he works and £9 per hour for any extra hours. Assuming that he works at least 40 hours, write an expression for his gross weekly wage in terms of H, the total hours worked per week, and then simplify it.