1/4 + 3/4x = -13/8 b)(x-3/2) ^2 +1/2=9/2 c)(x-3/5) : -1/3=0,4 d)(x-1)^5=32

Đáp án:

`a) 1/4 + 3/4 x = -13/8`

`3/4 x = -13/8 - 1/4`

`3/4 x = -13/8 - 2/8`

`3/4 x = -15/8`

`x = -15/8 : 3/4`

`x = -15/8 . 4/3`

`x = -5/2`

Vậy `x=-5/2`

`b) (x-3/2)^2 + 1/2 = 9/2`

`(x-3/2)^2 = 9/2 - 1/2`

`(x-3/2)^2 = 4`

`(x-3/2)^2 = 2^2 = (-2)^2`

`=> x-3/2 = 2` hoặc `x-3/2 = -2`

TH`1: x-3/2 =2`

        `x=2+3/2`

        `x= 4/2 + 3/2`

        `x=7/2`

TH`2: x-3/2 = -2`

        `x=-2+3/2`

        `x=-4/2 + 3/2`

        `x=-1/2`

Vậy `x in {7/2;-1/2}`

`c) (x-3/5) : (-1)/3 = 0,4`

`(x-3/5) : (-1)/3 = 2/5`

`x-3/5 = 2/5 . (-1)/3`

`x-3/5 = -2/15`

`x = -2/15 + 3/5`

`x = -2/15 + 9/15`

`x = 7/15`

Vậy `x=7/15`

`d) (x-1)^5 = 32`

`(x-1)^5 = 2^5`

`=> x-1 = 2`

      `x=2+1`

      `x=3`

Vậy `x=3`