Question

mn giúp mk vs

a)\(\dfrac{x-3}{4}=\dfrac{4}{x=3}\)

b)(x-1);5=(2x+1):3

c)\(\dfrac{37-x}{x+13}=\dfrac{3}{7}\)

d)\(\dfrac{x-1}{x+2}=\dfrac{x-2}{x+1}\)

e) \(\dfrac{x+4}{20}=\dfrac{5}{x+4}\)

Answer 1

b: \(\dfrac{x-1}{5}=\dfrac{2x+1}{3}\)

=>10x+5=3x-3

=>7x=-8

hay x=-8/7

c: \(\dfrac{37-x}{x+13}=\dfrac{3}{7}\)

=>259-7x=3x+39

=>-10x=-220

hay x=22

d: \(\dfrac{x-1}{x+2}=\dfrac{x-2}{x+1}\)

\(\Leftrightarrow\left(x-1\right)\left(x+1\right)=\left(x-2\right)\left(x+2\right)\)

\(\Leftrightarrow x^2-1=x^2-4\)(vô lý)

e: \(\dfrac{x+4}{20}=\dfrac{5}{x+4}\)

\(\Leftrightarrow\left(x+4\right)^2=100\)

=>x+4=10 hoặc x+4=-10

=>x=6 hoặc x=-14