You can do this with conditional formatting.
Select cell A2, then Format Conditional Formatting. Use the drop-down and
text box to make your condition 'Formula Is' '=(A2=A1)', then select the
format you want (red bold text) and click OK. Then use the format painter to
copy the format from A2 to other cells in the column.

"Pasquini" wrote:

I would like to format a cell to turn red and bold, when it is a number other
than the previous cell. And, I would like it to stay black when it is the
same number as the previous cell.

Ex.

A1=30 (Red & Bold)
A2=30 (Black)
A3=45 (Red & Bold)
A4=45 (Black)
A5=45 (Black)
etc.