Question

数学题求教。。在线等。。谢谢。

Answer 1

3. 原式=-12 a^2 - 40 a b - 12 b^2=-4 (3 a + b) (a + 3 b)
4. (m x - 3)^2= 9 - 6 m x + m^2 x^2
则 -6 m = 24, a = m^2,b=9
a=16, b=9 , m = -4 ,
5, 好像有点问题，无实数解
6.
x (x^2 + x y + y^2) - y (x^2 + x y + y^2) + 3 x y (-x + y)
=3 x y (-x + y) + (x - y) (x^2 + x y + y^2)
=-3 x (x - y) y + (x - y) (x^2 + x y + y^2)
=(x - y) (x^2 - 2 x y + y^2)
=(x - y) (x - y)^2
=(x - y)^3
=(3-2)^3
=1
7. (2 + 1) (2^2 + 1) (2^4 + 1) (2^8 + 1)
= (2-1) (2 + 1) (2^2 + 1) (2^4 + 1) (2^8 + 1) /(2-1)
=(2^2 - 1) (2^2 + 1) (2^4 + 1) (2^8 + 1) /(2-1)
= (2^4 -1)(2^4 + 1) (2^8 + 1) /(2-1)
= (2^8 - 1)(2^8 + 1) /(2-1)
=2^16-1
=65535

追问

谢谢啊

追答

不用谢，请采纳