(-a^2-1/2b)^2
=(a²+1/2b)²
=a的4次方+a²b+b²/4
(-3x-2y)(3x+2y)
=-(3x+2y)²
=-(9x²+12xy+4y²)
=-9x²-12xy-4y²
(2a-b )^2-4(b^2-ab)
=4a²-4ab+b²-4b²+4ab
=4a²-3b²
(-a^2-1/2b)^2
=(a²+1/2b)²
=a的4次方+a²b+b²/4
(-3x-2y)(3x+2y)
=-(3x+2y)²
=-(9x²+12xy+4y²)
=-9x²-12xy-4y²
(2a-b )^2-4(b^2-ab)
=4a²-4ab+b²-4b²+4ab
=4a²-3b²