|2x – 1/3|+3/2=2. C,(3^x-27)×(2 căn x -4)=0

2 bình luận về “|2x – 1/3|+3/2=2. C,(3^x-27)×(2 căn x -4)=0”

1. Giải đáp:

    |2x-\frac{1}{3}|+\frac{3}{2}=2

   => |2x-\frac{1}{3}|=2-\frac{3}{2}

   => |2x-\frac{1}{3}|=\frac{4}{2}-\frac{3}{2}

   => |2x-\frac{1}{3}|=\frac{1}{2}

   Xét 2TH:

   +)TH1: 2x-\frac{1}{3}=\frac{1}{2}

   => 2x=\frac{1}{2}+\frac{1}{3}

   => 2x=\frac{3}{6}+\frac{2}{6}

   => 2x=\frac{5}{6}

   => x=\frac{5}{6}:2

   => x=\frac{5}{12}

   +)TH2: 2x-\frac{1}{3}=\frac{-1}{2}

   => 2x=\frac{-1}{2}+\frac{1}{3}

   => 2x=\frac{-3}{6}+\frac{2}{6}

   => 2x=-\frac{1}{6}

   => x=(-\frac{1}{6}):2

   => x=-\frac{1}{12}

   Vậy x\in{\frac{5}{12};-\frac{1}{12}}

   c)

   (3^{x}-27).(2\sqrt{x}-4)=0

   Ta xét 2TH:

   +)TH1:

   3^{x}-27=0

   => 3^{x}=27

   => 3^{x}=3^{3}

   => x=3

   +)TH2: 2\sqrt{x}-4=0 (đk:x\ge0)

   => 2\sqrt{x}=4

   => \sqrt{x}=2

   => x=2^{2}

   => x=4 $\text{(Thoả mãn đk)}$

   Vậy x\in{3;4}

   #Dyna

   Trả lời
2. |2x – 1/3| + 3/2 = 2

   =>|2x – 1/3| = 1/2

   =>2x – 1/3 = 1/2 hoặc 2x – 1/3 = -1/2

   =>2x = 5/6 hoặc 2x = -1/6

   =>x = -1/12 hoặc x = 5/12

   c) (3x^x – 27) x(2 căn x – 4) = 0

   =>3^x – 27 = 0 hoặc 2căn x – 4 = 0

   =>x = 4 hoặc x = 3

   hay nhất nha

   Trả lời