Besoin d'aide pour les maths svp

Exercice 7

A= (5-t)² = 25 -10t +t²
B=(x-8)² = x² -16x +64
C=(4y-1)² = 16y² -8y +1
D=(3x-7) = 9x² -42x +49
E=(6-9w) = 36 -18w +81w²
F=(p-2,4) = p² -4,8p +5,76
G=(10q-1) = 100q² -20q +1
H=(1,4x-1) = 1.96x² -2.8x +1

Exercice 8

A=(x-2) (x+2) = x² -4
B=(5-y) (5+y) = 25 -y²
C= (3x+5) (3x-5) = 9x² -25
D= (10-7z) (10+7z) = 100 -49z²
E= (5+4g) (5-4g) = 25 -16g²
F= (2,1x-3) (2,1x+3) = 4,41x² -9
G= (2i+6,1) (2i-6,1) = 4i² -37,21
H= (3,2j+4) (4-3,2j) = 12,8j -3,2j² +16 -12,8j = -3,2j² +16