Verified answer

bonjour

niveau lycée ??

A = 6x * 2x + 6x * (-3) = 12x² - 18x

B = 5x*3x + 5x*7 - 4*3x - 4*7 = 15x² + 20x - 12x - 28 = 15x² + 8x - 28

C = 4 * 3x + 4 * 1 = 4 (3x+1)

d)  7x - 3x = 21 - 5

4x = 16

x = 4

E = 8¹⁵/8²⁰ = 8⁻⁵ (application directe cours)

F = 7/10 x (22/6 - 12/6)

F = 7/10 x 10/6 = 7/6