分解因式:2(3a²-b)-a(3b-4)已知m²-3m+1=0,求m²+m²分之1

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分解因式:2(3a²-b)-a(3b-4)已知m²-3m+1=0,求m²+m²分之1

分解因式:2(3a²-b)-a(3b-4)已知m²-3m+1=0,求m²+m²分之1
分解因式:2(3a²-b)-a(3b-4)
已知m²-3m+1=0,求m²+m²分之1

分解因式:2(3a²-b)-a(3b-4)已知m²-3m+1=0,求m²+m²分之1
3a^2-b)-a(3b-4)
=6a^2-2b-3ab+4a
=2a(3a+2)-b(3a+2)
=(2a-b)(3a+2)
m^2-3m+1=0,求m^2+1/m^2
m^2-3m+1=0
m-3+1/m=0
m^2+1/m^2=(m+1/m)^2-2=3^2-2=7

2(3a^2-b)-a(3b-4)
=6a^2-2b-3ab+4a
=2a(3a+2)-b(3a+2)
=(2a-b)(3a+2)
已知m^2-3m+1=0,求m^2+1/m^2
m^2-3m+1=0
m-3+1/m=0(两边同时除以m)
m+1/m=3
m^2+1/m^2=(m+1/m)^2-2=3^2-2=7

2*(3a^2-b)-a(3b-4)
=6a^2-2b-3ab+4a
=2a(3a+2)-b(3a+2)
=(3a+2)(2a-b)
m^2-3m+1=0
m^2=3m-1
1/(m^2+m^2)=1/(3m-1+3m-1)=1/2(3m-1)