Question

\(\frac{2}{5}:x=\frac{-1}{4};\frac{4}{7}.x-\frac{2}{3}=\frac{1}{5}\)  ai giải được mình cho 10 tck

 

Answer 1

\(\frac{2}{5}:x=-\frac{1}{4}\)
      \(x=\frac{2}{5}:-\frac{1}{4}\)
   \(x=\frac{2}{5}\cdot-\frac{4}{1}\)
      \(x=-\frac{8}{5}\)
Vậy \(x=-\frac{8}{5}\)
\(\frac{4}{7}\cdot x-\frac{2}{3}=\frac{1}{5} \)   
           \(\frac{4}{7}\cdot x=\frac{1}{5}+\frac{2}{3}\)
           \(\frac{4}{7}\cdot x=\frac{3}{15}+\frac{10}{15}\)
           \(\frac{4}{7}\cdot x=\frac{13}{15}\)
                   \(x=\frac{13}{15}:\frac{4}{7}\)
                   \(x=\frac{13}{15}\cdot\frac{7}{4}\)
                   \(x=\frac{91}{60}\)
 Vậy \(x=\frac{91}{60}\)
      

Answer 2

2/5 : x = -1/4

=> x = 2/5 : -1/4 

=> x = -8/5

4/7.x - 2/3 = 1/5

=> 4/7x = 1/5-2/3

=> 4/7x = -7/15

=> x = -49/60