Question

tìm các số nguyên x,y:

a, \(\dfrac{6}{2x+1}=\dfrac{2}{7}\)

b,\(\dfrac{24}{7x-3}=\dfrac{-4}{25}\)

c,\(\dfrac{4}{x-6}=\dfrac{y}{24}=\dfrac{-12}{18}\)

d,\(\dfrac{-1}{5}< \dfrac{x}{8}< \dfrac{1}{4}\)

Answer 1

a. \(\dfrac{6}{2x+1}=\dfrac{2}{7}\Rightarrow\dfrac{6}{2x+1}=\dfrac{6}{21}\Rightarrow2x+1=21\)

\(\Rightarrow2x=21-1=20\Rightarrow x=\dfrac{20}{2}=10\)

Vậy x = 10

b. \(\dfrac{24}{7x-3}=\dfrac{-4}{25}\Rightarrow\dfrac{24}{7x-3}=\dfrac{24}{150}\Rightarrow7x-3=150\)

\(\Rightarrow7x=150+3=153\Rightarrow x=\dfrac{153}{7}\)

Vậy \(x=\dfrac{153}{7}\)

c. \(\dfrac{4}{x-6}=\dfrac{-12}{18}\Rightarrow-12\cdot\left(x-6\right)=4\cdot18=72\)

\(\Rightarrow x-6=\dfrac{72}{-12}=-6\Rightarrow x=-6+6=0\)

\(\dfrac{y}{24}=\dfrac{-12}{18}\Rightarrow y=\dfrac{-12\cdot24}{18}=-16\)

Vậy x = 0 ; y = -16