Question

tìm số nguyên x, biết:

Answer 1

m)\(\dfrac{3}{4}=\dfrac{x}{x+1}\)
\(\Leftrightarrow3\left(x+1\right)=4x\)
\(\Rightarrow3x+3=4x\)
\(\Rightarrow3x+3-4x=0\)
\(\Rightarrow\left(3x-4x\right)+3=0\)

\(\Rightarrow-x=-3\)
\(\Rightarrow x=3\)
Vậy x = 3
p)\(\dfrac{5}{4x-2}=\dfrac{-1}{5-x}\)
\(\Leftrightarrow5\left(5-x\right)=\left(4x-2\right)\left(-1\right)\)
\(\Rightarrow25-5x=-4x+2\)
\(\Rightarrow25-5x+4x-2=0\)
\(\Rightarrow\left(-5x+4x\right)+\left(25-2\right)=0\)
\(\Rightarrow-x+23=0\)
\(\Rightarrow x=23\)
Vậy x = 23
#Kễnh

Answer 2

m: ĐKXĐ: x<>-1

\(\dfrac{3}{4}=\dfrac{x}{x+1}\)

=>4x=3(x+1)

=>4x=3x+3

=>4x-3x=3

=>x=3(nhận)

p: ĐKXĐ: \(x\notin\left\{5;\dfrac{1}{2}\right\}\)

\(\dfrac{5}{4x-2}=\dfrac{-1}{5-x}\)

=>\(5\left(5-x\right)=-1\cdot\left(4x-2\right)\)

=>\(25-5x=-4x+2\)

=>-5x+4x=2-25

=>-x=-23

=>x=23(nhận)