Question

bài 1:

\(a,\frac{1}{3}-\left(\frac{1}{2}+\frac{1}{8}\right)\)

\(b,\frac{1}{2}-\frac{1}{4}+\frac{1}{13}+\frac{1}{8}\)

\(c,13\frac{2}{7}:\left(\frac{-8}{9}\right)+2\frac{5}{7}:\left(\frac{-8}{9}\right)\)

Các bạn làm giúp mk nha

Làm đc phần nào thì làm

Ko cần làm hết 3 phần cũng đc

Answer 1

a) \(\frac{1}{3}-\left(\frac{1}{2}+\frac{1}{8}\right)\)

=   \(\frac{1}{3}-\left(\frac{4}{8}+\frac{1}{8}\right)\)

=     \(\frac{1}{3}-\frac{5}{8}\)

= \(\frac{8}{24}-\frac{15}{24}\)

= \(\frac{-7}{24}\)

b) \(\frac{1}{2}-\frac{1}{4}+\frac{1}{13}+\frac{1}{8}\)

= \(\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{8}\right)\)+ \(\frac{1}{13}\)

= \(\left(\frac{4}{8}-\frac{2}{8}+\frac{1}{8}\right)+\frac{1}{13}\)

=                 \(\frac{1}{8}+\frac{1}{13}\)

=                 \(\frac{13}{104}+\frac{8}{104}\)

=                        \(\frac{23}{104}\)

c) \(13\frac{2}{7}:\left(\frac{-8}{9}\right)+2\frac{5}{7}:\left(\frac{-8}{9}\right)\)

= \(\left(13\frac{2}{7}+2\frac{5}{7}\right):\left(\frac{-8}{9}\right)\)

=         \(16:\left(\frac{-8}{9}\right)\)

=         -18