Bài 1: Tìm x: a. 1/4 + 3/4 : x = -2 b. 1-(-3/4 + x ) : 8/3 =0 c. (4x-5 ) . ( 5/4 x – 2 ) =0 d. 1/2 x + 2/3 x – 1 = -8/3 * Mìn

1 bình luận về “Bài 1: Tìm x: a. 1/4 + 3/4 : x = -2 b. 1-(-3/4 + x ) : 8/3 =0 c. (4x-5 ) . ( 5/4 x – 2 ) =0 d. 1/2 x + 2/3 x – 1 = -8/3 * Mìn”

1. a.

   1/4+3/4:x=-2

   => 3/4:x=-2-1/4

   => 3/4:x=-9/4

   => x=3/4:(-9/4)

   => x=-1/3

   Vậy x=-1/3

   b.

   1-(-3/4+x):8/3=0

   => (-3/4+x):8/3=1

   => -3/4+x=1. 8/3

   => -3/4+x=8/3

   => x=8/3+3/4

   => x=41/12

   Vậy x=41/12

   c.

   (4x-5).(5/4x-2)=0

   TH1: 4x-5=0

   => 4x=5

   => x=5/4

   TH2: 5/4x-2=0

   => 5/4x=2

   => x=8/5

   Vậy x\in{5/4;8/5}

   d.

   1/2x+2/3x-1=-8/3

   => (1/2+2/3).x=-8/3+1

   => 7/6.x=-5/3

   => x=(-5/3):7/6

   => x=-10/7

   Vậy x=-10/7

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