please could someone help me with the last question ?

First you must declare a constant named product which should be the result for firstValue * secondValue right?

let product = firstValue * secondValue

Step 2: Using string interpolation, create a string literal that describes the operation we just performed. For example, given the following values for firstValue, secondValue and product respectively: 2, 4, 8. The string should read: "The product of 2 times 4 is 8". Assign this string to a constant named output.

Alright, so you now you have the make a string literal which explains the math you just did (using string interpolation*) and assign it to a constant named output

string interpolation is

\(anyConstant)

// i.e.

\(firstValue)

inside a string literal - which is text inside quotes i.e. let someString = "this is a string literal"

so the answer would be as follows:

let output = "The product of \(firstValue) times \(secondValue) is \(product)"

Happy coding!