Final answer:
The correct algebraic expression for 'Three times the difference of a number and 5' is 3(x - 5), which represents the multiplication of three times the difference between a variable 'x' and the number 5.
Step-by-step explanation:
The algebraic expression for “Three times the difference of a number and 5” is written by first representing the number with a variable, often x, and then indicating the difference between this number and 5 as (x - 5). Finally, to express 'three times' this difference, we multiply by 3, leading to the expression 3(x - 5). This corresponds to option a, which is the correct choice among the given options.
When you encounter phrases such as 'the difference of a number and 5,' it implies subtraction, where the number comes first (x - 5), followed by the multiplication by three to represent 'three times' which gives us 3(x - 5). Remember that the order in which we perform the operations matters. The difference (subtraction) must be calculated before the multiplication.