Assuming your target boxes are (-12x +36) and (8x -24), here are the classifications of the expressions with parentheses.
-3(4x + 12) = -12x -36 (neither)
-4(3x -9) = -12x +36
4(2x - 6) = 8x -24
-4(-2x - 6) = 8x +24 (neither)
3(-4x +12) = -12x +36
2(4x - 12) = 8x -24
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The distributive property applies:
... a(b+c) = ab +ac
Same signs multiply to give positive. Different signs multiply to give negative.
