(-3a+2b)(-3a-2b)
=9a²-4b²
(3/4x-4/3y)^2
=9/14x²-2xy+16/9y²
(0.5a+1/4)^2
=0.25a²+a+1/16
(-2a^2-7b)^2
=4a^4+28a²b+49b²
(-8b+1/4)^2
=64b²-4b+1/16
我怕了你了,今天怎么都是你的题目.拜托,把题目分开一点,好不好?