1) $$4(x-8) = 4 \cdot x - 4 \cdot 8 = 4x - 32$$
2) $$8(x+3) = 8 \cdot x + 8 \cdot 3 = 8x + 24$$
3) $$(7-x) \cdot 8 = 7 \cdot 8 - x \cdot 8 = 56 - 8x$$
4) $$(4a - c) \cdot 12 = 4a \cdot 12 - c \cdot 12 = 48a - 12c$$
5) $$9 (3a - 7b + 8c) = 9 \cdot 3a - 9 \cdot 7b + 9 \cdot 8c = 27a - 63b + 72c$$
6) $$(5x + 8y - 3k) \cdot 12 = 5x \cdot 12 + 8y \cdot 12 - 3k \cdot 12 = 60x + 96y - 36k$$