help with dragging formulas across

[BrutalLogiC]

hello this seems so simple but I can't work it out

I want columns A to Z to display values by multiplying the percentages in columns AA to AZ by the corresponding row values in fixed column BA.

e.g.
A1 = AA1*BA1
B1 = AB1*BA1
C1 = AC1*BA1
Z1 = AZ1*BA1
A2 = AA2*BA2
B2 = AB2*BA2
A500 = AA500*BA500

there's lots of cells to fill in A1 to AZ500... there must be a way to drag the cells across without changing them individually? sorry newb question

 

[Nishant94]

In cell A1:

=AA1*$BA1