Moltiplicazioni tra monomi ?

[matteo12319]

(x-y)(x+3y) =

(2a +3b)(3b-4a) =

(b^3 - 3a)(4x -y)(2x+y) =

(4x-y)(2x+y) =

(a^2-2a)(3a+(2a^2) =

[evelyn.allia]

1)(x-y)(x+3y) =
(x^2+3xy-xy-3y^2)
x^2+2xy-3y^2
2)(2a +3b)(3b-4a) =
6ab-8a^2+9b^2-12ab
-8a^2-6ab+9b^2
3)(b^3 - 3a)(4x -y)(2x+y) =
(4b^3x-b^3y-12ax+3ay)(2x+y)
8b^3x^2-2b^3xy-24ax^2+6axy+4b^3xy-b^3y^2-12axy+3ay^2
8b^3x^2+2b^3xy-24ax^2-6axy-b^3y^2+3ay^2
4)(4x-y)(2x+y)
8X^2+4xy-2xy-y^2
8x^2+2xy-y^2
5)(a^2-2a)(3a+(2a^2) =
3a^3+2a^4-6a^3-4a^3
2a^4-7a^3

[Studente Anonimo]

Ciao,
risolviamo le seguenti moltiplicazioni tra monomi:

1.
(x-y)(x+3y)=
x•x+x•3y-y•x-y•3y=
x²+3xy-xy-3y²=
sommiamo i termini simili
x²+2xy-3y²

2.(2a +3b)(3b-4a) =
2a•3b+2a•(-4a)+3b•3b+3b•(-4a)=
6ab-8a²+9b²-12ab=
-8a²-6ab+9b²

3.
(b³-3a)(4x -y)(2x+y) =
(b³•4x+b³•(-y)+(-3a)•(4x)+(-3a)(-y))(2x+y)=
(4xb³-yb³-12ax+3ay)(2x+y)=
4xb³•2x+4xb³•y-yb³•2x-yb³•y-12ax•2x-12ax•y+3ay•2x+3ay+y=
8x²b³+4xyb³-2xyb³-y²b³-24x²a-12xya+6xya+3y²a=
8x²b³+2xyb³-y²b³-24x²a-6xya+3y²a
4.
(4x-y)(2x+y) =
4x•2x+4x•y-y•2x-y•y=
8x²+4xy-2xy-y²=
8x²+2xy-y²

5.
(a²-2a)(3a+2a²) =
a²•3a+a²•2a²-2a•3a-2a•2a²=
3a³+2a⁴-6a²-4a³=
2a⁴-a³-6a²