1,原式=(m-2)n^2+(m-2)n-12(m-2)
=(m-2)(n^2+n-12)
=(m-2)(n-3)(n+4)
2, (m+2)/(4m-3)=-1得
m+2=3-4m m=1/5
(2m-1)/(m^2-3m-4)
=(2/5-1)/(1/25-3/5-4)
=(-3/5)/((1-15-100)/25)
=(-3/5)/(-114/25)
=15/114
=5/38
①分解因式吗(m-2)n²+(m-2)n-12m+24=(m-2)(n²+n-12)=(m-2)(n-3)(n+4)
②(m+2)/(4m-3)=-1
m+2=-(4m-3)
m+2=-4m+3
5m=1
m=1/5
(2m-1)/(m²-3m-4)=(2m-1)/[(m-4)(m+1)]=(-3/5)/[(-19/5)(6/5)]=5/38
①解:原式=(m-2)n^2+(m-2)n-12(m-2)=(m-2)(n^2+n-12)=(m-2)(n-3)(n+4)
②解:去分母,m+2=-4m+3∴m=1/5∴原式=(2/5-1)/(1/25-3/5-4)=(10-25)/(1-15-100)=15/114=5/38
楼主第一题什么意思?前边的是(m-2)的平方乘以n还是(m-2)n整体的平方?
第二题为由前式可得m+2=3-4m,解得m=1/5,带入后式中可得5/38