Question

tìm số nguyên x, biết:

 

Answer 1

g: \(\dfrac{x}{10}=\dfrac{3}{5}\)

=>\(x=\dfrac{3}{5}\cdot10\)

=>x=6

j: ĐKXĐ: x<>9

\(\dfrac{3}{5}=\dfrac{-12}{9-x}\)

=>\(\dfrac{3}{5}=\dfrac{12}{x-9}\)

=>\(x-9=12\cdot\dfrac{5}{3}=20\)

=>x=20+9=29(nhận)

Answer 2

g) \(\dfrac{x}{10}=\dfrac{3}{5}\)

\(\Rightarrow x=\dfrac{3}{5}\cdot10\)

\(\Rightarrow x=6\left(tm\right)\)

Vậy: \(x=6\).

j) \(\dfrac{3}{5}=\dfrac{-12}{9-x}\left(x\ne9\right)\)

\(\Rightarrow3\cdot\left(9-x\right)=-12\cdot5\)

\(\Rightarrow3\cdot\left(9-x\right)=-60\)

\(\Rightarrow9-x=-60:3\)

\(\Rightarrow9-x=-20\)

\(\Rightarrow x=9-\left(-20\right)\)

\(\Rightarrow x=9+20\)

\(\Rightarrow x=29\left(tm\right)\)

Vậy: \(x=29\).

Answer 3

\(g)\dfrac{x}{10}=\dfrac{3}{5}\\ \Rightarrow5x=3\cdot10\\ \Rightarrow5x=30\\ \Rightarrow x=\dfrac{30}{5}=6\\ j)\dfrac{3}{5}=\dfrac{-12}{9-x}\left(ĐK:x\ne9\right)\\ \Rightarrow3\left(9-x\right)=5\left(-12\right)\\ \Rightarrow27-3x=-60\\ \Rightarrow-3x=-60-27\\ \Rightarrow-3x=-87\\ \Rightarrow x=\dfrac{-87}{-3}=29\)