初一数学题(x+2y)^2(x^2+4y^2)^2(x-2y)^2-[X^4-(2y^4)^2]^2(x+2y)^2(x^2+4y^2)^2(x-2y)^2-[X^4-(2y^4)^2]^2要步骤
问题描述:
初一数学题(x+2y)^2(x^2+4y^2)^2(x-2y)^2-[X^4-(2y^4)^2]^2
(x+2y)^2(x^2+4y^2)^2(x-2y)^2-[X^4-(2y^4)^2]^2要步骤
答
x-y=4
2x+y=5
y=x-4
代入第二个
2x+x-4=5
3x=9
x=3
y=x-4=-1
2x-3y=-4
4x-5y=3
y=(2x+4)/3
代入第二个
4x-5(2x+4)/3=3
12x-10x-20=9
x=29/2
y=(2x+4)/3=11
2(x-1)-5y=2
3y-4(x-1)=-3
x-1=(5y+2)/2
代入第二个
3y-4(5y+2)/2=-3
3y-10y-4=-3
y=-1/7
x-1=(5y+2)/2=9/14
x=23/14
答
(2y^4)^2应该是(4y^2)^2
原式=[(x+2y)(x-2y)]^2(x^4+4y^2)]^2-(x^4-16y^4)^2
=(x^2-4y^2)^2(x^4+4y^2)]^2-(x^4-16y^4)^2
=(x^4-16y^4)^2-(x^4-16y^4)^2
=0