因式分解（5x-3y)^2-(3x-5y)^2

(1)
(5x-3y)^2-(3x-5y)^2
=[(5x-3y)+(3x-5y)][(5x-3y)-(3x-5y)]
=(8x-8y)(2x+2y)
=16(x+y)(x-y)
(2)
(a+2b)^2-4(a-b)^2
=(a+2b)^2-[2(a-b)]^2
=[(a+2b)+2(a-b)][(a+2b)-2(a-b)]
=3a(-a+4b)
(3)
(x+y)^2-4(x+y)+4
=[(x+y)-2]^2
=(x+y-2)^2
(4)
a^2-ab+b^2/4
=(a-b/2)^2