(x-2y-1)(x+2y-1)=(x-1-2y)(x-1+2y)=(x-1)²-4y²=x²-4y²-2x+1
(2a-b)²(4a²+b²)²(2a+b)²=[(2a-b)(2a+b)]²(4a²+b²)²=(4a²-b²)²(4a²+b²)²=(16a^4-b^4)²
=256a^8-32a^4b^4+b^8
(-0.6)^90×(-1 2/3)^100=(3/5)^90×(5/3)^100=(5/3)^(-90)×(5/3)^100=(5/3)^10