EXCEL column delete duplicate data

For example:A listing 1,3,4,5,7,8,9 B contains 3,4,7,8 desired result is the A column, directly 3,4,7,8 deleted directly 1.5.9.the actual situation, A contains 19,000 rows, B contains 2489 rows.to ask how this should write the formula?

Enter the following formula in C1, = if (countif (b:b, a1), “delete” “reservations”) fill down the formula, select the ABC series, screening, automated screening, C series selected to delete, then delete the A column filter results.show all, that is, you have to

thanks! again I ask, too the results, how to remove the blank space (in the A column)

do not know what the formula can be resolved.I am here to provide a solution:A column of data will be connected to the B column data back, then remove the duplicate data.then remove the pre-2489 lines.

as if to remove the extra phone number like a way to A, B out on two SHEET B single in the data behind the addition of a “repeat” with the VLOOKUP () A formula to find B, duplication is repeated Rights GOOD LUCK