Question 190500
Could someone please tell me if these problems are correct. 
I am working on a test and I am unsure. 
Multiply and simplify. (7y)^7*(7y)^4 Answer y^11 
It's (7y)^11
---------------
s^3+14s^2+49s Answer s(s+7)^2 Looks right.
--------------------
Simplify the expression (6^7)^4 Answer 10^21 
This is 6^28 
--------------
Simplify: 1/3^-4 Answer 81. Looks right.
--------------------
I am not sure about this can you explain d^3 when d=4. 
d^3 when d=4 is 4^3
4^3 = 64