ủa có mẫu r thì bn dựa vào mẫu mà lm

a) 3x5/4= 15/4

b) 1x2/3= 2/3

c) 3x4/5= 12/5

d) 3x1/4= 3/4 

\(1+2-3\times4:5=1+2-2,4=3-2,4=0,6\)

1+2-3x4:5

=1+2-2,4

=3-2,4

=0,6

1+2-3x4:5=1+2-12:5=3-2.4=0.6

 1+2-3x4:5

=3-2,4

=0,6

\(\frac{2}{3}\times\frac{4}{5}+\frac{1}{3}\times\frac{4}{5}\)

\(=\left(\frac{2}{3}+\frac{1}{3}\right)\times\frac{4}{5}\)

\(=1\times\frac{4}{5}\)

\(=\frac{4}{5}\)

2/3 x 4/5 + 1/3 x 4/5

= 4/5 x (2/3 + 1/3 )

= 4/5 x 1

= 4/5 

mong các bạn nha

Bằng một số

= 107/45 nha bạn 

nhớ mình đúng nha

hok tốt ^o^

\(\frac{1}{9}+\frac{2}{3}\times4-\frac{3}{5}\div\frac{3}{2}\)

\(=\frac{1}{9}+\frac{8}{3}-\frac{3}{5}\times\frac{2}{3}\)

\(=\frac{1}{9}+\frac{24}{9}-\frac{6}{15}\)

\(=\frac{25}{9}-\frac{6}{15}\)

\(=\frac{125}{45}-\frac{18}{45}\)

\(=\frac{107}{45}\)

a, = 8/15 x 5/6 = 40/90 = 4/9

b, = 5/6 x 1/5 = 5/30 = 1/6

a, \(= 8/15 x 5/6 = 40/90 = 4/9\)

b, \(= 5/6 x 1/5 = 5/30 = 1/6\)

\(5\dfrac{1}{3}\times\dfrac{4}{7}:\dfrac{3}{8}\)

\(=\dfrac{16}{3}\times\dfrac{4}{7}\times\dfrac{8}{3}\)

\(=\dfrac{16\times4\times8}{3\times7\times3}\)

\(=\dfrac{512}{63}\)