a. Pick a number. Next, subtract 3. Then double the result. Then subtract the original number. Finally, add 6. Compare your result with the original number.
b. Pick another number and follow the instructions in part (a), including comparing your result with the original number.
c. Let x be a number and follow the instructions in part (a). Your result should be an expression. Simplify the expression to explain the observations you made in parts (a) and (b).