Bonjour
a,b et c sont trois nombres tel que ab= -2 et ac= -3.
Prouvez que les nombres P,Q,R,S,T,U sont compris entre -65 et 25.
P=-9ab
P = -9 x (-2)
P = 18
Q=2/3a(3c-b)
Q = 2ac - 2ab/3
Q = 2 x (-3) - 2/3 x (-2)
Q = -6 + 4/3
Q = -18/3 + 4/3
Q = -14/3
R=-4a(b+c)
R = -4ab - 4ac
R = -4 x (-2) - 4 x (-3)
R = 8 + 12
R = 20
S=-10ax-10axbc
S = 100a^2bc
S = 100 x ab x ac
S = 100 x (-2) x (-3)
S = 600
T=-5ax(-b)
T = -5ab
T = -5 x (-2)
T = 10
U=-6b/7c
U = -6ab/(7ac)
U = -6 x (-2) / (7 x (-3))
U = (2 x 3 x 2)/(7 x (-3))
U = (-4/7)