Moltiplicazioni tra poli-monomi ?

[matteo12319]

(5/4 x^2 y -3/2 xy-15/12 y^3)(-8/15 x^2y)



(x^2 +3)(x^4 -3x^2 +9) =



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



(2a^2- 3a^3)(4a^2 + 6a^3)

[evelyn.allia]

1)(5/4x^2y-3/2xy-15/12y^3)(-8/15x^2y)
-2/3x^4y^2+4/5x^3y^2+2/3x^2y^4
2)(x^2 +3)(x^4 -3x^2 +9) =
x^6-3x^4+9x^2+3x^4-9x^2+27
x^6+27
3)(-2a+3b)(3a-2b) =
-6a^2+4ab+9ab-6b^2
-6a^2+13ab-6b^2
4)(2a^2- 3a^3)(4a^2 + 6a^3)
8a^4+12a^5-3a^5-18a^6
-18a^6+9a^5+8a^4

[Studente Anonimo]

Ciao,

(5/4 x²y -3/2xy-15/12 y³)(-8/15 x²y)=
(5/4)•(-8/15)x⁴y²+(-3/2)•(-8/15)x³y³+(-15/12)•(-8/15)x²y⁴=
-2/3x⁴y²+4/5x³y³+2/3x²y⁴


(x²+3)(x⁴-3x²+9) =
x⁶-3x⁴+9x²+3x⁴-9x²+27=
x⁶+27


(-2a+3b)(3a-2b) =
(-2)•(3)a²+(-2)•(-2)ab+(3•3)ab+(3)•(-2)b²=
-6a²+4ab+9ab-6b²
-6a²+13ab+9ab-6b²


(2a²-3a³)(4a²+ 6a³)=
(2•4)a⁴+(2•6)a⁵+(-3•4)a⁵+(-3•6)a⁶=
8a⁴+12a⁵-12a⁵-18a⁶=
8a⁴-18a⁶

saluti :-)