c + d) =
– 3 + a +
b + c + d– 7 + (– a – b – c – d) =
– 7 – a – b – c – d
10 + ( a + b – c + d) =
10 + a + b – c + d
(5a – 2b + 4c – 3d) * (– 3) =
– 15a + 6b – 12c + 9d
– 12 * (– 2a + 5b – 4c + 3d) =
24a – 60b + 48c – 36d
(– 3a – 2b + 5c + 4d) * (– 15) =
45a + 30b – 75c – 60d