Sagot :
bonjour
T = 3 x² + 12 x - 10 x - 40
T = 3 x² + 2 x - 40
si x = - 3
T = 3 ( - 3 )² + 2 ( -3 ) - 40
T = 27 - 6 - 40 = - 19
Bjr
1)
T = (3x-10)(x+4)
T = 3x×x+3x×4-10x-10×4
T = 3x²+3x×4-10x-10×4
T = 3x²+12x-10x-10×4
T = 3x²+12x-10x-40
T = 3x²+2x-40
2)
T = (3x-10)(x+4)
T = (3×(-3)-10)((-3)+4)
T = (-9-10)((-3+4)
T = (-9-10)(-3+4)
T = -19(-3+4)
T = -19×1
T = -19
Voilà !