Bonjour,
4×2,58 + 3 - 9×2,58 + 5 - 3×2,58 - 6 - 7 + 8×2,58
= (4 - 9 - 3 + 8) × 2,58 + 3 + 5 - 6 - 7
= 0 × 2,58 - 5
= 0 - 5
= -5
4×109 + 3 - 9×109 + 5 - 3×109 - 6 - 7 + 8×109
= (4 - 9 - 3 + 8) × 109 + 3 + 5 - 6 - 7
= 0 × 109 - 5
= 0 - 5
= -5
4×0,578 + 3 - 9×0,578 + 5 - 3×0,578 - 6 - 7 + 8×0,578
= (4 - 9 - 3 + 8) × 0,578 + 3 + 5 - 6 - 7
= 0 × 0,578 - 5
= 0 - 5
= -5