(1) a(a+2)-(a-1)(a+1)
=a²+2-a²+1
=3
(2)(2x+5)²-(2x-5)²
=(2x+5+2x-5)(2x+5-2x+5)
=4x×10
=40x
(3) (-2X-1)²-4(X-1)(X+2)
=4x²+4x+1-4x²-4x+8
=9
(4) 3a(2a²-4a)-2a²(3a+4) a=-1
=6a³-12a²-6a³-8a²
=-20a²
=-20
(5) (X-2)(x²-6x)-x(x²-2x-8) x=2
=x³-6x²-2x²+12x-x³+2x²+8x
=-6x²+20x
=-24+40
=16
(6) 10(a+5)²-10a² a=5
=10a²+100a+250-10a²
=500+1250
=1750
(7)化简 2a(1+x%)²-a(1-x%)²
=2a+4ax%+2ax%²-a+2ax%-ax%²
=a+6ax%ax%²。