Bjr
La politesse svp
Pour x = 4,2
A = 3(5×4,2-6)
A = 3(21-6)
A = 3×15
A = 45
B = 5×4,2×2+6
B = 42+6
B = 48
Pour x = 1,5
A = 3(5×1,5-6)
A = 3(7,5-6)
A = 3×1,5
A = 4,5
B = 5×1,5×2+6
B = 15+6
B = 21
Pour x = -3
A = 3(5×(-3)-6)
A = 3(-15-6)
A = 3(-21)
A = -63
B = 5×(-3)×2+6
B = -30+6
B = -24
Voilà !