Hỗn số

M = 15 
-> 15 . 40 = 600

600

15x40=600

=13/5

\(=\dfrac{2\times5+3}{5}=\dfrac{13}{5}\)

13/5

cả 2 bài ạ

\(x-3\dfrac{2}{5}=1\dfrac{1}{5}\)

\(\Leftrightarrow x-\dfrac{17}{5}=\dfrac{6}{5}\)

\(\Leftrightarrow x=\dfrac{6}{5}+\dfrac{17}{5}\)

\(\Leftrightarrow x=\dfrac{23}{5}\)

x+\(3\dfrac{1}{5}\)=4

x=4-\(3\dfrac{1}{5}\)

x=\(\dfrac{4}{5}\)

\(x+3\dfrac{1}{5}=4\)

\(x+\dfrac{16}{5}=4\)

          \(x=4-\dfrac{16}{5}\)

          \(x=\dfrac{4}{5}\)

a, \(x+\dfrac{16}{5}=4\)

\(x=4-\dfrac{16}{5}\)

\(\Rightarrow x=\dfrac{4}{5}\)

\(40.\)

\(a\)) \(S\)

\(b\)) Đ

\(c\)) Đ

\(d\)) \(S\)

\(41.\)

\(a\)) \(1\dfrac{1}{3}+2\dfrac{1}{2}=\dfrac{4}{3}+\dfrac{5}{2}=\dfrac{23}{6}\)

\(b\)) \(3\dfrac{2}{5}-1\dfrac{1}{10}=\dfrac{17}{5}-\dfrac{11}{10}=\dfrac{23}{10}\)

\(c\)) \(3\dfrac{1}{2}.1\dfrac{1}{7}=\dfrac{7}{2}.\dfrac{8}{7}=\dfrac{56}{14}=4\)

\(d\)) \(4\dfrac{1}{6}:2\dfrac{1}{3}=\dfrac{25}{6}:\dfrac{7}{3}=\dfrac{25}{14}\)

a)83/12

b)255/14

Đáp án:

a) \(\dfrac{83}{12}\)

b) \(\dfrac{255}{14}\)

Hok tốt

\(\dfrac{3}{4}+1\dfrac{5}{6}=\dfrac{3}{4}+\dfrac{11}{6}=\dfrac{9}{12}+\dfrac{22}{12}=\dfrac{31}{12}\)

=3/4+11/6=31/12

3/4 + 11/6= 31/12

1:

a: =15/7*31/8=465/56

b: =29/5-7/6=139/30

c: =25/6+19/5=239/30

2:

a: =44/5:7/2=88/35

b: =10/3+11/9+5/9=46/9