how to solve 3a+2[2+3a(a-1)]=2(3a+4)

Answer 1

(1) Multiply out both sides
(2) Combine a^2, "a" terms and constants separately
(3) Solve for a

Here is step 1:
3a + 4 +6a^2 -6a = 6a + 8

Here is part of step 2
6a^2 - 9a -___ = 0

Take it from there. You will end up with a quadratic equation to solve; there will be two answers.