Bonjour,
E = (x-1)²-(x+1)(x-2)-3
= (x²-2x+1)-(x²-2x+x-2)-3
= (x²-2x+1)-(x²-x-2)-3
= x²-2x+1-x²+x+2-3
= x²-x²-2x+x+1+2-3
= -x
si x = 6 943 875
alors : x-1 = 6 943 875 - 1 = 6 943 874
x+1 = 6 943 875 + 1 = 6 943 876
x-2 = 6 943 875 - 2 = 6 943 873
donc : 6 943 874² - 6 943 876 × 6 943 873 - 3
= (6 943 875 - 1)² - (6 943 875 + 1) × (6 943 875 - 2) - 3
= - 6 943 875
