(x+2)(2-x)(4+x^2)=? (2ax^3)(-2ax^3-3ax)=? (x^2-2y)(2x+y^2)=? (a+b-c)^2=? (1-?)^2=9x^2+?=?(x+2)(2-x)(4+x^2)=(4-x²)(

(x+2)(2-x)(4+x^2)=(4-x²)(4+x²)=16-x^4
(2ax^3)(-2ax^3-3ax)=(-2a²x^4)(2x²+3)
(x^2-2y)(2x+y^2)=2x³+x²y²-2xy-2y³
(a+b-c)^2=a²+b²+c²+2ab-2bc-2ac
(1-3x)^2=9x^2-6x+1

(-x-1)^2=x^2+2x+1
(3+b)^2=(3-b)^2+12b
(x-1)^2=(x+1)^2+(-4)
(-m²-n^3)^2=m^4+2m²n^3+n^6

---

(x+2)(2-x)(4+x^2)=(4-x²)(4+x²)=16-x^4
(2ax^3)(-2ax^3-3ax)=(-2a²x^4)(2x²+3)
(x^2-2y)(2x+y^2)=2x³+x²y²-2xy-2y³
(a+b-c)^2=a²+b²+c²+2ab-2bc-2ac
(1-3x)^2=9x^2-6x+1

(-x-1)^2=x^2+2x+1
(3+b)^2=(3-b)^2+12b
(x-1)^2=(x+1)^2+(-4)
(-m²-n^3)^2=m^4+2m²n^3+n^6

---

(x+2)(2-x)(4+x^2)=（4-x^2)(4+x^2)=16-x^4 不是，这个题什么意思

---