Completely factor the following expressions.

1. 256z^2-4-192z^2+3

2. 2a^2c^3-14bc^3+32c^3d^2

3. 35g^2+6g-9

4. 3j^3-51j^2+210j

1.

collect terms
64z^2 - 1
(8z-1)(8z+1)

2.
factor out the c^3
c^3(2a^2-14b+32d^2)

3.
(5g+3)(7g-3)

4.
factor out the 3j
3j(j^2 - 17j + 70)
3j(j-7)(j-10)