3(x-1)×(2x-1)=5(x+8)(x-1)

2 bình luận về “3(x-1)×(2x-1)=5(x+8)(x-1)”

1. 3(x-1)(2x-1)=5(x+8)(x-1)

   <=>3[2x^2-x-2x+1]=5[x^2-x+8x-8]

   <=>6x^2-9x+3=5x^2+35x-40

   <=>6x^2-9x+3-5x^2-35x+40=0

   <=>x^2-44x+43=0

   <=>(x-43)(x-1)=0

   <=>$[\begin{array}{l}x-43=0\\ x-1=0\end{array}$ 

   <=>$[\begin{array}{l}x=43\\ x=1\end{array}$ 

   Vậy Phương Trình có tập nghiệm S={43;1}

   Trả lời
2. 3(x-1).(2x-1)=5.(x+8).(x-1)

   <=> [3(x-1)].(2x-1)=[5.(x+8)].(x-1)

   <=> (3x-3).(2x-1)=(5x+40).(x-1)

   <=> $\text{[(3x)(2x)]+[(3x).(-1)]+[(-3).(2x)]+[(-3)(-1)] = [(5x)x] + [(5x).(-1)]+[40x+(40).(-1)] }$

   <=>  6x^{2}-3x-6x+3 =   5x^{2} – 5x + 40x -40

   <=> 6x^{2}-3x-6x+3-  5x^{2} + 5x -40x +40= 0

   <=>  6x^{2}-  5x^{2}-3x-6x+ 5x -40x+3+40 = 0

   <=> x^{2} – 44x + 43 = 0

   <=> (x – 1).(x – 43) = 0

   $\text{ 2 trường hợp}$

   $[\begin{array}{l}x–1=0\\ x–43=0\end{array}$

   <=> $[\begin{array}{l}x=1\\ x=43\end{array}$

   $\text{ Vậy S= {1 ; 43} }$

   Trả lời