Développer,puis réduire chaque expression a) 5x(3x-1)-10x au carré(petit -2 le au carre ) b)6x(-2+3)-4x c)(x+3)(2x-1) d)(5-3x)(4x-7)

[tex]a)5x(3x+1)-10 x^{2} \\=15x^{2} +5x-10 x^{2} \\=5 x^{2} +5x[/tex]

[tex]b)6x(-2+3)-4x\\=-12x+18x-4x \\=2x[/tex]

[tex]c)(x+3)(2x-1) \\=2 x^{2} -x+6x-3 \\=2 x^{2} +5x-3[/tex]

[tex]d)(5-3x)(4x-7) \\=20x-35-12 x^{2} +21x \\= -12 x^{2} +41x-35[/tex]

a=5x(3x-1)-(10x)²
=15x²-5x-100x²
=-85x²-5x
b=6x(-2+3)-4x
=-12x+18x-4x
=2x
c=(x+3)(2x-1)
=2x²-x+6x-3
=2x²+5x-3
d=(5-3x)(4x-7)
=20x-35-12x²+21x
=41x-12x²-35