Question

tìm x, biết

1. \(\frac{x+1}{x-2}=\frac{3}{4}\)

2. \(\frac{52}{2x-1}=\frac{13}{30}\)

3.\(\frac{2x-3}{x+1}=\frac{4}{7}\)

4. \(\frac{2x+3}{42}=\frac{3x-1}{32}\)

Answer 1

1.\(\frac{x+1}{x-2}=\frac{3}{4}\)

\(\Leftrightarrow\left(x+1\right).4=\left(x-2\right).3\)

\(\Leftrightarrow4x+4=3x-6\)

<=>4x-3x=-6-4

<=>x=-10

 

2.\(\frac{52}{2x-1}=\frac{13}{30}\)

<=>52.30=(2x-1).13

<=>1560=26x-13

<=>-26x=-13-1560

<=>-26x=-1573

<=>x=60,5

 

3.\(\frac{2x-3}{x+1}=\frac{4}{7}\)

<=>(2x-3).7=(x+1).4

<=>14x-21=4x+4

<=>14x-4x=4+21

<=>10x=25

<=>x=2,5

 

4.\(\frac{2x+3}{42}=\frac{3x-1}{32}\)

<=>(2x+3).32=42(3x-1)

<=>64x+96=126x-42

<=>64x-126x=-42-96

<=>-62x=-138

<=>x=69/31

 

Answer 2

cho mk hỏi 

10x=25 số 10 ở đâu vậy bn