Question

[Phạm Lan Anh]

Bài1: Tính
a) \(\dfrac{-5}{7}\) - \(\dfrac{1}{3}\)                           c) \(\dfrac{-1}{16}\) -\(\dfrac{1}{15}\)

b) \(\dfrac{-3}{8}\) + \(\dfrac{2}{5}\)                          d) \(\dfrac{-2}{5}\) - \(\dfrac{-3}{4}\) 
Bài 2: Tính ( số nguyên với phân số)
a) 1 - \(\dfrac{3}{4}\)                               b)1 -  \(\dfrac{1}{2}\)

c) \(\dfrac{1}{5}\) - 2                               d) -5 - \(\dfrac{1}{6}\)

Bài 3: Tìm x biết
a) \(\dfrac{-5}{8}\) + x =\(\dfrac{-7}{6}\)                             b) x - \(\dfrac{-3}{4}\) = \(\dfrac{-14}{25}\)

c) x + \(\dfrac{1}{-6}\) =\(\dfrac{4}{3}\)                    

Answer 1

[Nguyễn Thị Thương Hoài]

Bài 1:

a; \(\dfrac{-5}{7}\) - \(\dfrac{1}{3}\)

   = \(\dfrac{-15}{21}\) - \(\dfrac{7}{21}\)

   = \(\dfrac{-22}{21}\)

b; \(\dfrac{-3}{8}\) + \(\dfrac{2}{5}\)

 =   \(\dfrac{-15}{40}\) + \(\dfrac{16}{40}\)

 = \(\dfrac{1}{40}\);

c; \(\dfrac{-1}{16}\) - \(\dfrac{1}{15}\)

= \(\dfrac{-15}{240}\) - \(\dfrac{16}{240}\)

= \(\dfrac{-31}{240}\)

d; \(\dfrac{-2}{5}\) - \(\dfrac{-3}{4}\)

= \(\dfrac{-8}{20}\) + \(\dfrac{15}{20}\)

= \(\dfrac{7}{20}\)

Answer 2

[Nguyễn Lê Phước Thịnh]

Bài 3:

a: \(-\dfrac{5}{8}+x=-\dfrac{7}{6}\)

=>\(x=-\dfrac{7}{6}+\dfrac{5}{8}\)

=>\(x=\dfrac{-28+15}{24}=\dfrac{-13}{24}\)

b: \(x-\dfrac{-3}{4}=-\dfrac{14}{25}\)

=>\(x=-\dfrac{14}{25}+\dfrac{-3}{4}\)

=>\(x=\dfrac{-56+\left(-75\right)}{100}=\dfrac{-131}{100}\)

c: \(x+\dfrac{1}{-6}=\dfrac{4}{3}\)

=>\(x=\dfrac{4}{3}+\dfrac{1}{6}\)

=>\(x=\dfrac{8}{6}+\dfrac{1}{6}=\dfrac{9}{6}=\dfrac{3}{2}\)