Bonsoir :)
1. A = (3+5) x (-9+3)
A = 8 x (-6)
A = -48
B = 10/[6 - 2x(1-0,5)] x 2
B = 10/[6 - 2 x 0,5] x 2
B = 10/(6 - 1) x 2
B = 10/5x2
B = 10/10
B = 1
C = -3^4 - 23 x 10 - (14 - 2 x 18)
C = -81 - 230 - (14 - 36)
C = -81 - 230 - 14 + 36
C = -289
D = (7x - 2)² c'est une identité remarquable :)
D = 49x² - 28x + 4
E = (2x - 3)(2x + 3) ça aussi :)
E = 4x² - 9
F = x(2x + 4) - 5
F = 2x² + 4x - 5