Question

[Huyền Trang Tiến Tài]

tìm x

a, 31-2/x+23=9/4

b, |2x-1|/1\2=18/5

c,x-2/x-1=x+4/x+7

h, 3x+2/5x+7=3x-1/5x-3

Answer 1

[Nguyễn Lê Phước Thịnh]

c: \(\dfrac{x-2}{x-1}=\dfrac{x+4}{x+7}\)

=>(x-2)(x+7)=(x+4)(x-1)

\(\Leftrightarrow x^2+5x-35=x^2+3x-4\)

=>5x-35=3x-4

=>2x=31

hay x=31/2

h: \(\dfrac{3x+2}{5x+7}=\dfrac{3x-1}{5x-3}\)

\(\Leftrightarrow\left(3x+2\right)\left(5x-3\right)=\left(3x-1\right)\left(5x+7\right)\)

\(\Leftrightarrow15x^2-9x+10x-6=15x^2+21x-5x-7\)

=>x-6=16x-7

=>-15x=-1

hay x=1/15