Đáp án:
Giải thích các bước giải:
a) $\frac{1}{15}$ - x = $\frac{3}{10}$
=> x= $\frac{1}{15}$ - $\frac{3}{10}$
=> x = $\frac{-7}{30}$
Vậy x =$\frac{-7}{30}$
b)$\frac{5}{12}$ + $\frac{5}{x}$ - $\frac{1}{8}$ = $\frac{1}{2}$
=> $\frac{5}{12}$ + $\frac{5}{x}$ = $\frac{1}{2}$ + $\frac{1}{8}$
=> $\frac{5}{12}$ + $\frac{5}{x}$ = $\frac{5}{8}$
=> $\frac{5}{x}$ = $\frac{5}{12}$ - $\frac{5}{8}$
=> $\frac{5}{x}$ = $\frac{-5}{24}$
=> -5x = 5 . 24
=> -5x = 100
=> x = 20
Vậy x = 20
c) $\frac{4}{10}$ - x = $\frac{-3}{20}$ + $\frac{3}{5}$
=> $\frac{4}{10}$ - x = $\frac{9}{20}$
=> x = $\frac{4}{10}$ - $\frac{9}{20}$
=> x = $\frac{-1}{20}$
Vậy x = $\frac{-1}{20}$
