The answer you’re looking for is: simplify.
When you rewrite an expression, we are simplifying it. We first use the distributive property through any groupings symbols, then evaluate terms we exponent that are given. Lastly, we combine any like terms, weather they are constants or variables.
Hope this helps! :)
20 and 0 are your answers
Since each stapler costs 16.99, the total cost is 16.99*x, with x representing the number of staplers bought. This works due to that he adds 16.99 for every stapler, and multiplying it adds 16.99 each time he buys a new stapler