Answer: formula
Step-by-step explanation:
The expression =d8-d17 is called a formula in a spreadsheet. A formula is an instruction that tells the spreadsheet program to perform a calculation using specific cells or values. In this case, the formula is telling the spreadsheet to subtract the value in cell D17 from the value in cell D8. The result of the calculation will be displayed in the cell where the formula is entered. Formulas can include a variety of different operators, such as + for addition, - for subtraction, * for multiplication, and / for division, as well as functions that perform more complex calculations.