D= x(x+1)-(3-x)(2x-1)
= x² + x - ( 6 x - 3 - 2 x² + x )
= x² + x - 6 x + 3 + 2 x² - x
= 3 x² - 6 x + 3
E=(3-2x)(3x-1)+3(x²-2x)
= 9 x - 3 - 6 x² + 2 x + 3 x² - 6 x
= - 3 x² + 5 x - 3
F = (3-2x) (y+ 3 a. (a-5)² incompréhensible
=
a. (a-5)² = a² - 10 a + 25
c. (4-5x)² = 16 - 40 x + 25 x²
e. (7a-8)(7a+8) = 49 a² - 64
b. (5x+3)² = 25 x² + 30 x + 9
d. (t-6)(t+6) = t² - 36
f. (3u+2t)² = 9 u² + 12 ut + 4 t²
