Bonjour,
Voici la première partie
R= (4a+3) (3a+5)
R= 4a*3a+4a*5+3*3a+3*5
R= 12a2+20a+9a+15
R= 12a2+ 29a+ 15
S= (3a-2)(4a-7)
S= 3a*4a+3a*(-7)-2*4a-2*7
S= 12a2-21a-8a-21
S= 12a2-29a-21
T=(5a+7)(4a+1)
T= 5a*4a+5a*1+7*4a+7*1
T= 20a2+5a+28a+7
T= 20a2+33a+7
U= (-3a+2)(5a-4)
U= -3a*5a-3a*(-4)+2*5a+2*(-4)
U= -15a2+12a+10a-8
U= -15a2+22a-8
V= (2b-3)(2b-7)
V= 2b*2b+2b*(-7)-3*2b-3*(-7)
V= 4b2-14b-6b+21
V= 4b2-20b+21
W= (3a-4)(4a-11)
W= 3a*4a+3a*(-11)-4*4a-4*(-11)
W= 12a2-33a-16a+44
W= 12a2-49a+44