1.化簡：
原式=4（x+1)^2-7(x^2-1)+3(x-1)^2
=4（x+1)^2-7(x^2-1)+3(x^2-1)
=4（x+1)^2-4(x^2-1)
=4x^2+8x+4-4x^2+4
=8x+8
當(dāng)x=-2時,原式=8×（-2）+8
=-8
2.化簡：
原式=(2x-5y^2-(5y+2x)^2
=(5y-2x)^2-(5y+2x)^2
=(5y-2x+5y+2x)(5y-2x-5y-2x)
=10y×（-4x)
=-40xy
當(dāng)x=2011,y=-1/2011時,原式=-40×2011×-1/2011
=40
第三題題目再發(fā)你下,是不是：（a+b）（a-b）+a（2b-a）?