The exponent form of this repeated multiplication, (-4)(-4), is (-4)².
The exponent 2 signifies the number of times the base number is multiplied by itself.
(-4)² is the exponential form. The term (-4) is the base. ² is the exponent. Regardless if the form is in its exponential form or in its expanded form, the product is always equal in both forms.
(-4)² = 16
(-4)*(-4) = 16