f,$(x-2)^{2}$ - $5(2-x)^{}$ =0
⇔$(x-2)^{2}$ + $5(x-2)^{}$=0
⇔$(x-2)^{}$$(x+3)^{}$=0
⇔$\left \{ {{x=2} \atop {x=-3}} \right.$
g,$3x^{}$($x-1^{}$)-$x^{2}$+$2x^{}$-$1^{}$=0
⇔$3x^{}$($x-1^{}$)-$(x-1)^{2}$ =0
⇔$(x-1)^{}$($2x^{}$-$1^{}$)=0
⇔ $\left \{ {{x=1} \atop {x=\frac{1}{2}}} \right.$
h,$x^{2}$$(x-3)^{2}$ +27-9x=0
⇔$x^{2}$$(x-3)^{2}$-9(x-3)=0
⇔(x-3)($x^{2}$-9)
⇔$(x-3)^{2}$(x+3)=0
⇔ $\left \{ {{x=3} \atop {x=-3}} \right.$
i,$(5-x)^{2}$-25=0
⇔(5-x-5)(5-x+5)=0
⇔-x(10-x) =0
⇔$\left \{ {{x=0} \atop {x=10}} \right.$
BẠN CHO MÌNH CTLHN NHA :(
