Câu 1\(\frac{9}{8}.\frac{9}{3}=\frac{81}{24}\)

Câu 2 \(\frac{19}{5}+\frac{9}{5}=\frac{28}{5}\)

Câu 3 \(\frac{31}{7}:\frac{22}{5}=\frac{31.5}{7.22}=\frac{155}{154}\)

Câu 4 \(\frac{12}{1}-\frac{31}{5}=\frac{60}{5}-\frac{31}{5}=\frac{29}{5}\)

ai k mình mình k lại

1 + 1 = 2

3 + 3 = 6

5 + 5 = 10

1 + 0 = 1

99 + 1 = 100

9 + 1 = 10

5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 5 + 5 + 5 + 7 + 7 + 7 = 88

k mk nha

2

6

10

1

100

10

83

= 2/21

=9/5

=37/6:\(6\frac{1}{6}\)

=79/20: tự đổi nhe bạn

=3/5__________-

\(\frac{4}{15}x\frac{5}{14}=\frac{4x5}{15x14}=\frac{2x1}{3x7}=\frac{2}{21}\)

\(\frac{3}{4}:\frac{5}{12}=\frac{3}{4}x\frac{12}{5}=\frac{3x12}{4x5}=\frac{3x3}{1x5}=\frac{9}{5}=1,8\)

\(\frac{7}{2}+\frac{8}{3}=\frac{7x3}{2x3}+\frac{8x2}{3x2}=\frac{21}{6}+\frac{16}{6}=\frac{21+16}{6}=\frac{37}{6}\)

a, Sai

b, Đúng

c, đúng 

d, Sai

a,\(2\frac{2}{5}+1\frac{2}{5}=3\frac{2}{5}\left(S\right)\)

b,\(6\frac{3}{4}-1\frac{1}{4}=5\frac{2}{4}\left(\text{Đ}\right)\)

c,\(3\frac{1}{2}\times2\frac{2}{3}=9\frac{1}{3}\left(\text{Đ}\right)\)

d,\(4\frac{1}{6}\div2\frac{1}{5}=2\frac{5}{6}\left(S\right)\)

biết làm nhưng tui lười ko muốn viết dài

a, 2\(\dfrac{3}{5}\) \(\times\) 1\(\dfrac{1}{4}\) + \(\dfrac{5}{2}\)

= \(\dfrac{13}{5}\) \(\times\) \(\dfrac{5}{4}\) + \(\dfrac{5}{2}\)

= \(\dfrac{13}{4}\) + \(\dfrac{5}{2}\)

= \(\dfrac{13}{4}\) + \(\dfrac{10}{4}\)

= \(\dfrac{23}{4}\)

a, 7/5 : x + 3/2 = 16/3

7/5 : x = 16/3 - 3/2

7/5 : x = 23/6

x = 7/5 : 23/6

x = 42/115

b, x : 1/5 + 1/7 = 3/5 . 18/21

x : 1/5 + 1/7 = 18/35

x : 1/5 = 18/35 - 1/7

x : 1/5 = 13/35

x = 13/35 . 1/5

x = 13/175

c, x - 1 và 1/3 : 2 = 5/7

x - 4/3 : 2 = 5/7

x - 4/3 = 5/7 . 2

x - 4/3 = 10/7

x = 10/7 + 4/3

x = 58/21

d, x + 2 và 3/5 . 1/6 = 35/36

x + 13/5 . 1/6 = 35/36

x + 13/5 = 35/36 : 1/6

x + 13/5 = 35/6

x = 35/6 - 13/5

x = 97/30

e, ( x + 3/2 ) : 2 = 7/10 + 1/5

( x + 3/2 ) : 2 = 9/10

x + 3/2 = 9/10 . 2

x + 3/2 = 9/5

x = 9/5 - 3/2

x = 3/10

a ) \(1\frac{1}{2}+2\frac{1}{3}+3\frac{1}{6}-5\)

\(=\frac{3}{2}+\frac{7}{3}+\frac{19}{6}-\frac{5}{1}\)

\(=\frac{9}{6}+\frac{14}{6}+\frac{19}{6}-\frac{30}{6}\)

\(=\frac{23}{6}+\frac{19}{6}-\frac{30}{6}\)

\(=\frac{42}{6}-\frac{30}{6}\)

\(=\frac{12}{6}=2\)

b ) \(2\frac{2}{3}\times3\frac{3}{4}\div4\frac{4}{5}\)

\(=\frac{8}{3}\times\frac{15}{4}\div\frac{24}{5}\)

\(=\frac{120}{12}\div\frac{24}{5}\)

\(=\frac{120}{12}\times\frac{5}{24}\)

\(=\frac{600}{288}=\frac{25}{12}\)

c ) \(4\frac{1}{5}+5\frac{1}{3}-2\frac{2}{3}\times3\frac{1}{5}+\frac{9}{25}\div\frac{9}{20}\)

\(=\frac{21}{5}+\frac{16}{3}-\frac{8}{3}\times\frac{16}{5}+\frac{9}{25}\div\frac{9}{20}\)

\(=\frac{63}{15}+\frac{80}{15}-\frac{128}{15}+\frac{9}{25}\times\frac{20}{9}\)

\(=\frac{143}{15}-\frac{128}{15}+\frac{180}{225}\)

\(=\frac{15}{15}+\frac{12}{15}\)

\(=\frac{27}{15}=\frac{9}{5}\)

ai giải được

\(8\frac{7}{10}+2\frac{3}{4}=\frac{87}{10}+\frac{11}{4}=\frac{174}{20}+\frac{55}{20}=\frac{229}{20}\)

Bạn chỉ cần đưa về phân số xong tính bình thường. Muốn đổi từ hỗn số sang phân số, ta chỉ cần lấy phần nguyên nhân cho mẫu rồi cộng với tử là xong. Chứ bạn cứ hỏi mấy bài dễ như thế này thì k giỏi đc đâu!!!

\(a,2\frac{1}{18}+3\frac{5}{6}+1\frac{2}{3}\)

\(=2+\frac{1}{18}+3+\frac{5}{6}+1+\frac{2}{3}\)

\(=(2+3+1)+(\frac{1}{18}+\frac{5}{6}+\frac{2}{3})\)

\(=6+(\frac{1}{18}+\frac{15}{18}+\frac{12}{18})\)

\(=6+\frac{28}{18}\)

\(=6+\frac{14}{9}=7\frac{5}{9}=\frac{68}{9}\)

\(b,5\frac{3}{7}+(2\frac{5}{21}-1\frac{2}{3})\)

\(=5+\frac{3}{7}+2+\frac{5}{21}-1-\frac{2}{3}\)

\(=(5+2-1)+(\frac{3}{7}+\frac{5}{21}-\frac{2}{3})\)

\(=6+(\frac{9}{21}+\frac{5}{21}-\frac{14}{21})\)

\(=6+0=6\)

Chúc bạn học tốt

a) \(2\frac{1}{8}+3\frac{5}{6}+1\frac{2}{3}\)

\(=2\frac{3}{24}+3\frac{20}{24}+1\frac{16}{24}\)

\(=\left(2+3+1\right)+\frac{3+20+16}{24}\)

\(=6+\frac{13}{8}\)

\(=7\frac{5}{8}=\frac{61}{8}\)

b)\(5\frac{3}{7}+\left(2\frac{5}{21}-1\frac{2}{3}\right)\)

\(=5\frac{9}{21}+\left(2\frac{5}{21}-1\frac{14}{21}\right)\)

\(=5\frac{9}{21}+2\frac{5}{21}-1-\frac{14}{21}\)

\(=\left(5+2-1\right)+\frac{9+5-14}{21}\)

\(=6+0=6\)

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

\(=3+\frac{2}{5}+\frac{3}{5}\)

\(=3+1\)

\(=4\)