两题因式分解4xy^-4x^y-y(三次方)169(x+y)^-81(x-y)^要有完整的解答过程

4xy2-4x2y-y3
=y(4xy-4x2-y2)
=y(-4x2+4xy-y2)
=y[-(4x2-4xy+y2)]
=y{-[(2x)2-4xy+y2]}
=y[-(2x-y)2]
=-y(2x-y)2
169(x+y)2-81(x-y)2
=[13(x+y)^2]-[9(x-y)]^2
=[13(x+y)+9(x-y)][13(x+y)-9(x-y)]
=(22x+4y)(4x+22y)
=4(11x+2y)(2x+11y).

4xy^2-4x^2y-y^3
=-y(-4xy+4x^2+y^2)
=-y(2x-y)^2;
169(x+y)^2-81(x-y)^2
=[13(x+y)^2]-[9(x-y)]^2
=[13(x+y)+9(x-y)][13(x+y)-9(x-y)]
=(22x+4y)(4x+22y)
=4(11x+2y)(2x+11y).