Mikä on potenssimerkintöjen kantaluku?

a) [[$\left(\dfrac{2}{5}\right)^4$]]
Kantaluku on

b) [[$\dfrac{2^3}{7}$]]
Kantaluku on

c) [[$\left(-\dfrac{1}{3}\right)^2$]]
Kantaluku on

d) [[$-\left(2- \dfrac{1}{3}\right)^6$]]
Kantaluku on

e) [[$(a+7)^3$]]
Kantaluku on

f) [[$-\dfrac{4a^3}{3}$]]
Kantaluku on