a)2

b)75/37

c)0

d)8/27

e)7/19

f)4

ok

a) \(\frac{2}{9}+\frac{1}{5}+\frac{7}{9}+\frac{4}{5}=\left(\frac{2}{9}+\frac{7}{9}\right)+\left(\frac{1}{5}+\frac{4}{5}\right)= 1+1=2 \)

b) \(\frac{19}{37}+\left(1+\frac{19}{37}\right)=\left(\frac{19}{37}-\frac{19}{37}\right)+1=0+1=1\)

c) \(\frac{9}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)+\frac{7}{8}=\frac{9}{8}+\frac{7}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)=2-2=0\)

d) \(\frac{3}{5}\times\frac{8}{27}\times\frac{5}{3}=\frac{3}{5}\times\frac{5}{3}\times\frac{8}{27}=1\times\frac{8}{27}=\frac{8}{27}\)

e) \(\frac{7}{19}\times\frac{1}{3}+\frac{7}{19}\times\frac{2}{3}=\frac{7}{19}\times\left(\frac{1}{3}+\frac{2}{3}\right)=\frac{7}{19}\times1=\frac{7}{19}\)

f) \(\frac{12}{5}\times4-4\times\frac{7}{5}=4\times\left(\frac{12}{5}-\frac{7}{5}\right)=4\times1=4\)

6 + 7 + 9 + 8 + 10 + 5 + 5 = 50

\(6+7+9+8+10+5+5=50\)\(50\)

k mk 3 cái nha mí bn

9+0=9

7+3=10

5+5=10

2+8=10

Chúc bạn học giỏi nha!!!

\(9+0=9\)

\(7+3=10\)

\(5+5=10\)

\(2+8=10\)

k mk nha mí bn

a,

2/7:2/5=4/35

b,

(8/15+7/15):2/11=11/2

toán 1 sao?

\(\frac{3}{5\cdot7}+\frac{3}{7\cdot9}+...+\frac{5}{53\cdot55}\)

\(=\frac{3}{2}\cdot\left(\frac{2}{5\cdot7}+\frac{2}{7\cdot9}+...+\frac{2}{53\cdot55}\right)\)

\(=\frac{3}{2}\cdot\left(\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{53}-\frac{1}{55}\right)\)

\(=\frac{3}{2}\cdot\left(\frac{1}{5}-\frac{1}{55}\right)\)

\(=\frac{3}{2}\cdot\left(\frac{11}{55}-\frac{1}{55}\right)\)

\(=\frac{3}{2}\cdot\frac{10}{55}\)

\(=\frac{3}{2}\cdot\frac{2}{11}\)

\(=\frac{3}{11}\)

bằng 37 

nha bn k mk nha bn

T H A N K   Y O U

\(4+5+6+7+8+9-2=37\)

k mk , mk k lại

8  + 9 + 8 + 0 + 7 + 5  +  4 + 1 = 42 

tích mình nha, mình tích lại cho  

42 bạn nhé

k mình nha

\(\frac{5}{2}+\frac{2}{7}=\frac{39}{14}\)

Ncty là j:))

\(\sqrt{2.\sqrt{4}}\)\(=\sqrt{2.2}\)\(=\sqrt{4}\)\(=2\)

\(23+223+2223+22223=24692\)

\(\frac{7}{5}:\frac{5}{4}=\frac{7}{5}.\frac{4}{5}=\frac{28}{25}\)

1 + 2 + 3 + 4 + 5+ 6 + 7 + 8 + 9 = 45

lấy các số chẵn cộng lại vs nhau

\(1+2+3+4+5+6+7+8+9=45\)