Marla will use the formula to find the updated cost.
=A2-A4-A6-A8-A10
Because A2 is budget and A4, A6, A8 and A10 all are expenses. So she has to budget-all expenses.
So option A=A2-A4-A6-A8-A10 is true.
What is a spreadsheet?
A spreadsheet is a computer program that can capture, display and manipulate data arranged in rows and columns. Spreadsheets are one of the most popular tools available with personal computers.
A single spreadsheet can be used as a worksheet to compile data for a purpose, or multiple sheets can be combined to create an entire workbook.
Learn more about spreadsheet here,
https://brainly.com/question/10509036
#SPJ1