数学题(急)(1)7x^2-63(2)a^3-a(3)3a^2-3b^2(4)y^2-9(x+y)^2(5)a(x-y)-b(y-x)+c(x-y)(6)x(m+n)-y(n+m)+(m+n)(7)(x+y)^2-16(x-y)^2(8)a^2(a-b)^2-b^2(a+b)^2(9)(x+y+z)^2-(x-y-z)^2(10)(x+y)^2-14(x+y)+49(1)a^2b^2-0.01(2)x^2y-2xy^2+y^3(3)16-(2a+3b)^2(4)(a^2+4)^2

Question

数学题(急)
(1)7x^2-63
(2)a^3-a
(3)3a^2-3b^2
(4)y^2-9(x+y)^2
(5)a(x-y)-b(y-x)+c(x-y)
(6)x(m+n)-y(n+m)+(m+n)
(7)(x+y)^2-16(x-y)^2
(8)a^2(a-b)^2-b^2(a+b)^2
(9)(x+y+z)^2-(x-y-z)^2
(10)(x+y)^2-14(x+y)+49
(1)a^2b^2-0.01
(2)x^2y-2xy^2+y^3
(3)16-(2a+3b)^2
(4)(a^2+4)^2-16a^2
(5)x^2-xy+1/4y^2
(6)a^2x^2+16ax+64
(7)a^4-8a^2b^2+16b^4
(8)9+6(a+b)+(a+b)^2

Answer 1

(1)7x^2-63 =7(x^2-9)=7(x+3)(x-3)(2)a^3-a =a(a^2-1)=a(a+1)(a-1)(3)3a^2-3b^2=3(a^2-b^2)=3(a+b)(a-b) (4)y^2-9(x+y)^2=[y+3(x+y)][y-3(x+y)]=(3x+4y)(-3x-2y)(5)a(x-y)-b(y-x)+c(x-y)=a(x-y)+b(x-y)+c(x-y)=(a+b+...