Question

( 2 . x - 5 ) ³ = 8

6 chia het ( x - 1 )

mong cac ban giup, minh can gap truoc 9h

Answer 1

\(\left(2x-5\right)^3=8\)

\(\left(2x-5\right)^3=2^3\)

\(2x-5=2\)

\(2x=7\)

\(x=\frac{7}{2}\)

\(b,6⋮x-1\)

\(\Rightarrow x-1\inƯ6\left(\pm1,\pm2,\pm3\right)\)

+ x-1 =1 => x=2

+ x-1 =-1 =>x=0

+ x-1=2 =>x=3

+ x-1=-2 => x= -1

+ x-1 =3 =>x=4

+ x-1=-3 => x=-2

Answer 2

#Giải :

( 2x - 5 )³ = 8

( 2x - 5 )³ = 2³

=> 2x - 5 = 2

     2x = 7

       x = 7/2

6 chia hết cho ( x - 1 )

=> (x - 1) € Ư (6)

Ư (6) = { 1 ; 2 ; 3 ; 6 }

Nếu x - 1 = 1 => x = 2

Nếu x - 1 = 2 => x = 3

Nếu x - 1 = 3 => x = 4

Nếu x - 1 = 6 => x = 7

   [ P/S : € - thuộc ]

       #By_Ami 

Answer 3

a) (2x-5)³=8

    (2x-5)³=2³

     2x-5   =2

     2x       =2+5

     2x       =7

       x       =7/2

b) \(6⋮\left(x-1\right)\)

\(\Rightarrow x-1\inƯ\left(6\right)\)

\(\Rightarrow x-1\in\left\{-1;-2;-3;-6;1;2;3;6\right\}\)

\(\Rightarrow x\in\left\{0;-1;-2;-5;2;3;4;7\right\}\)

     Hok tốt nha!!!