Toán $m^{3}$ – $4m^{2}$ + $9m$ – $6$ $Tìm$ $m$ 17/07/2021 By Jasmine $m^{3}$ – $4m^{2}$ + $9m$ – $6$ $Tìm$ $m$
`m^3-4m^2+9m-6=0` `<=>m^3-m^2-3m^2+3m+6m-6=0` `<=>m^2(m-1)-3m(m-1)+6(m-1)=0` `<=>(m^2-3m+6)(m-1)=0` `<=>`\(\left[ \begin{array}{l}m^{2}-3m+6=0\\m-1=0\end{array} \right.\) `<=>m=1(vì m^2-3m+6`$\neq$ `0)` cm `m^2-3m+6`$\neq$ `0` `=m^2-2.cc3/2m+9/4+15/4` `=(m+3/2)^2+15/4` vì `(m+3/2)^2>=0;15/4>0∀m` `=>(m+9/4)^2+15/4>0` hay `m^2-3m+6`$\neq$ `0` vậy `m=1` xin hay nhất ạ Trả lời
`m^3-4m^2+9m-6=0`
`<=>m^3-m^2-3m^2+3m+6m-6=0`
`<=>m^2(m-1)-3m(m-1)+6(m-1)=0`
`<=>(m^2-3m+6)(m-1)=0`
`<=>`\(\left[ \begin{array}{l}m^{2}-3m+6=0\\m-1=0\end{array} \right.\) `<=>m=1(vì m^2-3m+6`$\neq$ `0)`
cm `m^2-3m+6`$\neq$ `0`
`=m^2-2.cc3/2m+9/4+15/4`
`=(m+3/2)^2+15/4`
vì `(m+3/2)^2>=0;15/4>0∀m`
`=>(m+9/4)^2+15/4>0`
hay `m^2-3m+6`$\neq$ `0`
vậy `m=1`
xin hay nhất ạ