:(1)x2+3x+2(2)x2﹣3x+2(3)x2+2x﹣3(4)x2﹣2x﹣3(5)x2+5x+6(6)x2﹣5x﹣6(7)x2+x﹣6(8)x2﹣x﹣6(9)x2﹣5x﹣36(10)x2+3x﹣18(11)2x2﹣3x+1(12)6x2+5x﹣6. :(1)2a+2a2+4a3(2)5x3y﹣5xy(3)a2+b2+2ab﹣16(4)4x3﹣8x2+4x(5)(x+y)2﹣2x﹣2y+1(6)(m2﹣2m)2n+2n(m2﹣2m)+n(7)(x2+y2﹣1)2﹣4x2y2(8)a(2a﹣b)+2a(b﹣2a)2﹣a(b﹣2a)3. 3.(1)已知x2+4x+y2﹣2y+5=0,求x,y.(2)a,b满足a(a+1)﹣(a2+2b)=1,求a2﹣4ab+4b2﹣2a+4b的值.(3)已知a2+b2=5,a+b=3,求(a﹣b)2.(4)已知x2﹣y2=20,求[(x﹣y)2+4xy][(x+y)2﹣4xy]的值.
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