bonsoir
A = (x+3)(x-2) = x² - 2 x + 3 x - 6 = x² + x - 6
B = (2x +4)² = 4 x² + 16 x + 16
C = (x+5)(x-5) = x² - 25
D = x(3x+4)+5 = 3 x² + 4 x + 5
E = (x-3)² = x² - 6 x + 9
F = (2x+3)²-(x+2)² = 4 x² + 12 x + 9 - ( x² + 4 x + 4 )
= 4 x² + 12 x + 9 - x² - 4 x - 4
= 3 x² + 8 x + 5