Sagot :
Bonjour,
a) A = 7(2x+3)-4(3-4y)
A = 14x+21-12+16y
A = 14x+9+16y
b) B = 4/3(-6x+1/2)-1/3(-3x-1)
B = -8x+2/3+x+1/3
B = -7x+1
c) C = 2x(3x-5)
C = 2x×3x-2x×5
C = 6x²-10x
d) D = (2x+3)(3x+4)
D = 2x×3x+2x×4+3×3x+3×4
D = 6x²+8x+9x+12
D = 6x²+17x+12
7(2x+3)-4(3-4y)
=(7×2x)+(7×3)-(4×3)+(4×4y)
=14x+21-12+16y
=16y+14x+9
4/3(-6x+1/2)-1/3(-3x-1)
=-(4/3×6x)+(4/3×1/2)+(1/3×3x)+(1/3×1)
=-8x+2/3+x+1/3
=-7x+1
2x(3x-5)
=(2x×3x)-(2x×5)
=6x^2-10x
(2x+3)(3x+4)
=(2x×3x)+(2x×4)+(3×3x)+(3×4)
=6x^2+8x+9x+12
=6x^2+17x+12