Decompose each multiple of tens hundreds or thousands before multiplying

Use the multiplier method to incrases £258 by 43%

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?

Is a positive integer raised to a negative power always positive