Subtract. (-d2 + 12d - 4) - (-7d2 - 2d + 12) =

The answer would be 26d - 16

I am using d^2 instead of d2 as that seems written incorrectly.

Same for - 7d^2 instead of - 7d2.

Start by changing the signs in the 2nd parenthesis by changing the subtract sign to a plus.

(-d^2 + 12d - 4) + (7d^2 + 2d - 12)

Now combine like terms

(7d^2 - d^2) + (12d + 2d) + - 4 + - 12

6d^2 + 14d + - 16 (or 6d^2 + 14d - 16)