Conditional formatting two cells based on a checkbox

dls5u 

Set the cell link for each check box to the cell it's in, so for example the cell link of the first check box should be C3.

This will set the value of cell C3 to TRUE or FALSE depending on the state of the check box. If you don't want to see this, apply the custom number format ;;; to the cells with the check boxes.

Select A3:B14.

On the Home tab of the ribbon, select Conditional Formatting > New Rule...

Select 'Use a formula to determine which cells to format'.

Enter the formula =$C3

Click Format...

On the Font tab, tick the Strikethrough check box.

Click OK, then click OK again.