Bài 1:
a) 4 - 1$\frac{2}{5}$ - $\frac{8}{3}$ = 2$\frac{3}{5}$ - $\frac{8}{3}$ = -$\frac{1}{15}$
b) $\frac{4}{5}$ - ( - $\frac{2}{7}$ ) - $\frac{7}{10}$
= $\frac{4}{5}$ + $\frac{2}{7}$ - $\frac{7}{10}$
= $\frac{38}{35}$ - $\frac{7}{10}$
= $\frac{27}{70}$
c) $\frac{3}{4}$ - [$\frac{3}{4}$ - ($\frac{2}{3}$ + $\frac{5}{6}$)]
= $\frac{3}{4}$ - [$\frac{3}{4}$ - ($\frac{2}{3}$ + $\frac{5}{6}$)]
= $\frac{3}{4}$ - [$\frac{3}{4}$ - $\frac{2}{3}$ - $\frac{5}{6}$]
= $\frac{3}{4}$ - $\frac{3}{4}$ + $\frac{2}{3}$ + $\frac{5}{6}$
= 0 + $\frac{2}{3}$ + $\frac{5}{6}$
= 0 + 1$\frac{1}{2}$
= 1$\frac{1}{2}$
Bài 2:
a) -x - $\frac{7}{4}$ = $\frac{17}{6}$
-x = $\frac{17}{6}$ + $\frac{7}{4}$
-x = 4$\frac{7}{12}$
-x = $\frac{55}{12}$
=> x = $\frac{12}{55}$
b) x - 0,25 = $\frac{-3}{8}$
x - $\frac{1}{4}$ = $\frac{-3}{8}$
x - $\frac{2}{8}$ = $\frac{-3}{8}$
x = $\frac{-3}{8}$ + $\frac{2}{8}$
x = $\frac{-1}{8}$
Chúc học tốt!!!
