当x=2^999,y=(-2)^999时,代数式4x^2-8xy+4y^2的值为
问题描述：
当x=2^999,y=(-2)^999时,代数式4x^2-8xy+4y^2的值为
答
4x²-8xy+4y²
=4(x²-2xy+y²)
=4(x-y)²
=4[2^999-(-2)^999]²
=4×4×2^1998
=2^4×2^1998
=2²ºº²
答
4x^2-8xy+4y^2
=4(x^2-2xy+y^2)
=4(x-y)^2
=4[2^999-(-2)^999]^2
=4(2×2^999)^2
=16×2^1998
答
2^(2002)
答
等于2^2002
答
4x^2-8xy+4y^2
=4(x^2-2xy+y^2)
=4(x-y)^2
=4(2^999-(-2)^999)^2
=4*(*2^999)^2
=4*(2^1000)^2
=4^2*2^2000
=2^(2002)