Question

1. Tìm x ϵ Z 

\(\frac{x-1}{9}\)= \(\frac{8}{3}\)

\(\frac{x}{4}\)  =  \(\frac{18}{x+1}\)

2. Cho A = \(\frac{3n-5}{n+4}\)  . Tìm n ϵ Z để A có giá trị nguyên

Các bn làm nhanh giúp mk nha !

Answer 1

\(\frac{x-1}{9}=\frac{8}{3}\Rightarrow\)\(\frac{x-1}{9}=\frac{24}{9}\Rightarrow x-1=24\)

                                        x=24+1

                                        x=25

Vậy x=25

 

Answer 2

\(\frac{x-1}{9}=\frac{8}{3}\)

\(\Leftrightarrow\left(x-1\right):9=\frac{8}{3}\)

\(\Leftrightarrow\left(x-1\right)=24\)

\(\Leftrightarrow x=24+1\)

\(\Leftrightarrow x=25\)

 

 

 

 

Answer 3

\(\frac{x-1}{9}\)=\(\frac{8}{3}\)

\(\Rightarrow\)\(\frac{x-1}{9}\)=\(\frac{24}{9}\)

\(\Rightarrow\)x-1=24

Vậy x =25

 

Answer 4

\(\frac{x}{4}=\frac{18}{x+1}\)

\(\Rightarrow\)x.(x+1)=4.18

    x.(x+1)=72

x.x+x=72

\(\Leftrightarrow\)x=8

Vậy x=8