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问几个问题:m-n=6,mn=2,则(m+3)(n-3)= (-2)^2011*(-1/2)^2012= a大于0,a^

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问几个问题:m-n=6,mn=2,则(m+3)(n-3)= (-2)^2011*(-1/2)^2012= a大于0,a^x=2,a^y=5,则a^2x-2y=
(2x-y-3z)(-2x-y+3x)
(a-b-c)^2-(a+b-c)^2
6*(7+1)*(7^2+1)*(7^4+1)*(7^8+1)+1
问几个问题:m-n=6,mn=2,则(m+3)(n-3)= (-2)^2011*(-1/2)^2012= a大于0,a^
m-n=6,mn=2,
(m+3)(n-3)
=mn-3m+3n-9
=mn-3(m-n)-9
=2-3*6-9
=-25
(-2)^2011*(-1/2)^2012
=(-2)^2011*(-1/2)^2012*(-1/2)
=[(-2)*(-1/2)^]2011*(-1/2)
=2^2011*(-1/2)
=-1/2
a^x=2,a^y=5
a^(2x-2y)
=a^2x/a^2y
=(a^x)^2/(a^y)^2
=2^2/5^2
=4/25
(2x-y-3z)(-2x-y+3z)
=-(2x-y-3z)(2x+y-3z)
=-(2x-3z-y)(2x-3z+y)
=-[(2x-3z)^2-y^2]
=-(4x^2+9z^2-12xz-y^2)
=-4x^2-9z^2+12xz+y^2
(a-b-c)^2-(a+b-c)^2
=[(a-b-c)-(a+b-c)][(a-b-c)+(a+b-c)]
=(a-b-c-a-b+c)(a-b-c+a+b-c)
=-2b(2a-2c)
=-4b(a-c)
=-4ab+4ac
6*(7+1)*(7^2+1)*(7^4+1)*(7^8+1)+1
=(7-1)*(7+1)*(7^2+1)*(7^4+1)*(7^8+1)+1
=(7^2-1)*(7^2+1)*(7^4+1)*(7^8+1)+1
=(7^4-1)*(7^4+1)*(7^8+1)+1
=(7^8-1)*(7^8+1)+1
=7^16-1+1
=7^16
再问: 全对吗?
再答: 当然
再问: 谢谢,如果检查无误就给分