Question

tìm x biết 3x/2.5+3x/5.8+3x/8.11+3x/11.14 = 1/21

Answer 1

sao 0 có kết quả                                                                          

Answer 2

3x/2.5 + 3x/5.8+3x/8.11+3x/11.14 = 1/21

 x(1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14) = 1/21

 x(1/2-1/14) = 1/21

x . 3/7 = 1/21

=> x = 1/21 : 3/7 

=> x = 1/9

Hihi mình giải zầy mk hk bik đúng hay sai

 

Answer 3

\(\frac{3x}{2.5}+\frac{3x}{5.8}+\frac{3x}{8.11}+\frac{3x}{11.14}=\frac{1}{21}\)

\(x.\left(\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}\right)\)\(=\frac{1}{21}\)

\(x.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}\right)\)\(=\frac{1}{21}\)

\(x.\left(\frac{1}{2}-\frac{1}{4}\right)\)\(=\frac{1}{21}\)

\(x.\frac{3}{7}=\frac{1}{21}\)

\(x=\frac{1}{21}:\frac{3}{7}\)

\(x=\frac{1}{9}\)

Answer 4

3x/2.5 + 3x/5.8+3x/8.11+3x/11.14 = 1/21

 x(1/2-1/5+1/5-1/8+1/8-1/11+1/11-1/14) = 1/21

 x(1/2-1/14) = 1/21

x . 3/7 = 1/21

=> x = 1/21 : 3/7 

=> x = 1/9

                                                       HT