Excel formulas are expressions used to perform computation.
The formula in Excel is: =($B$6 - $B$5 - $B$7)* $B$8
From the question, we are to:
To use the absolute reference in Excel cells, we have to include the dollar "$" sign.
This means that: a cell A1 will be written as: $A$1;
So, the formula to enter in cell B13 is:
=($B$6 - $B$5 - $B$7)* $B$8
Read more about Excel formulas at:
https://brainly.com/question/14820723