sum if weekday is equal to the weekday excel

i would like to solve some syntax error due to lack of skills. I would like to bind this weekday check with one formula. =IF(WEEKDAY(A11)=2,"Monday",IF(WEEKDAY(A11)=3,"Tuesday",IF(WEEKDAY(A11)=4,"Wednesday",IF(WEEKDAY(A11)=5,"Thursday",IF(WEEKDAY(A11)=6,"Friday")*(W11/X11*Y11*1.25))))) This is wrong and i need to sum up the (W11/X11*Y11*1.25) part and showing the day of transaction is only on weekdays and not weekend. Thank You In Advance

=IF(WEEKDAY(A11)=2,"Monday",IF(WEEKDAY(A11)=3,"Tuesday",IF(WEEKDAY(A11)=4,"Wednesday",IF(WEEKDAY(A11)=5,"Thursday",IF(WEEKDAY(A11)=6,"Friday")*(W11/X11*Y11*1.25)))))

No error message, the syntaxs is wrong