Hi Rosa,
Not too sure I follow, however:
If your X's are in column A (From Row 2 down to Row 101) and you want
the SLOPE with Y's in columns B,C,D etc I think you would use
SLOPE(B$2:B$101,$A$2:$A$101) then fill across to apply the same formula
to the other columns of Y values with the same X values in column A.
Or, apply a Name to the data column you want to repeatedly use then use
that name in the Slope formula.

Ken Johnson