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1,北京好大夫在线问答

老7冷滴的
http://beijing.haodf.com/

北京好大夫在线问答

2,家庭医生在线问答

有好几天,流鼻血了还有点打喷嚏流鼻涕,吃了莲芝消炎片和复方氨酚烷胶囊没见好转,请问.医生吃什么药能好转
有可能是感受寒邪了,口服点祛风通络的追风透骨丸有效果

家庭医生在线问答

3,数学题在线解答网

2(x+3y)(x-2y)-3(2x+y)(2x-3y)+5(x-2y)(x+2y) =2(x2-2xy+3xy-6y2)-3(4x2-6xy+2xy-3y2)+5(x2-4y2) =2x2-12x2+5x2-4xy+6xy+18xy-6xy-12y2+9y2-20y2 =-5x2+14xy-23y2 (m-5n)(m-n)-6(m+2n)(m-3n) =m2-mn-5mn+5n2-6(m2-3mn+2mn-6n2) =m2-6m2-mn-5mn+18mn-12mn+5n2+36n2 =-5m2+41n2 (x-6)(x-9) -(x-7)(x-1) <7(2x-5) x2-9x-6x+54-(x2-x-7x+7)<14x-35 -15x+54+8x-7-14x+35<0 -21x+82<0 21x>82 x>82/21 x(2x-3)(2x+3)-(x-3)(x2+9)-(2x2-1)(x+2),其中x=-2 原式=x(4x2-9)-(x3+9x-3x2-27)-(2x 3+4x2-x-2) =4x3-x3-2x3+3x2-4x2-9x-9x+x+27+2 = x3-x2-17x+29 ∵x=-2 ∴原式=-8-4+34+29=51

数学题在线解答网


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