Bonjour,
3(2x-3) = 3(2x) + 3(-3) = 6x-9
5x(7-4x) = 5x(7) + 5x(-4) = 35x-20x²
7 843 = 7,843 × 1 000 = 7,843 × 10³
0,0054 = 5,4 ÷ 1 000 = 5,4 × 10⁻³
37,21 × 10²⁰ = 3,721 × 10²¹
