12-[20-2(6^2-3x2^2)]
Start with the inner most parenthesis, and it's exponents:
(6^2-3x2^2)
6^2 = 36
2^2 = 4
36-4 = 32
Then multiply it by the coefficient (the number right outside the parenthesis). Then subtract from 20.
[20-2(32)]
[20- 64]
[-44]
And subtract from the outer number, remembering that a double negative is a positive.
12- [-44] = 12+44
56
