Question

Tìm x\(\in\)Z,biết:

a)3x-2\(⋮\)x+3

b)x\(⋮\)(2x+1)

c)3x+6\(⋮\)x+1

d)x²\(⋮\)x-2

Answer 1

a, 3x - 2 ⋮ x + 3

=> 3x + 9 - 11 ⋮ x + 3

=> 3(x + 3) - 11 ⋮ x + 3

=> 11 ⋮ x + 3

b, x ⋮ 2x + 1

=> 2x ⋮ 2x + 1

=> 2x + 1 - 1 ⋮ 2x + 1

=> 1 ⋮ 2x + 1

c, 3x + 6 ⋮ x + 1

=> 3x + 3 + 3 ⋮ x + 1

=> 3(x + 1) + 3 ⋮ x + 1

=> 3 ⋮ x + 1

d, em không biết làm

Answer 2

câu a,b,c bn Cả Út lm r 

mik làm câu d

\(x^2⋮x-2\)

\(\Rightarrow x\left(x-2\right)+2x⋮x-2\)

\(\Rightarrow2x⋮x-2\)

\(\Rightarrow2\left(x-2\right)+4⋮x-2\)

\(\Rightarrow4⋮x-2\)

\(\Rightarrow x-2\inƯ\left(4\right)=\left\{\pm1;\pm2;\pm4\right\}\)

\(\Rightarrow n\in\left\{3;1;4;0;6;-2\right\}\)

Vậy..............................