bonjour
A = 6 x 10 ⁵ x 10 ⁻⁸ sur 8 x 10 ⁻²
= 6 x 10 ⁻³ sur 8 x 10 ⁻²
= 0.75 x 10 ⁻¹
= 7.5 x 10 ⁻²
B = - 9 + 10 ³ - ( - 8)
= - 9 + 1 000 + 8
= 999
= 9 .99 x 10 ²
C = 12 - 0.0008 sur 300
= 11.9992 /300
= 0.039997333
= 3.9997333 x 10 ⁻²
D = ( - 10 + 9 * 2) ² - ( - 5)²
= ( - 10 + 18)² - ( 25)
= 8² - 25
= 64 - 25 = 39 = 3.9 x 10