Lời giải:

$=(\frac{3}{5}+\frac{2}{5})+(\frac{5}{11}+\frac{16}{11})+(\frac{7}{13}+\frac{19}{13})$

$=\frac{5}{5}+\frac{22}{11}=\frac{26}{13}=1+2+2=5$

ở chỗ 19?16 là em viết sai thật là 19/16 ạ

Mọi người trả lời nhanh giúp em với ạ

Giúp mik vs mik cung đang cân

\(\frac{3}{5}+\frac{5}{1}+\frac{7}{13}\)\(+\frac{2}{5}+\frac{16}{11}+\frac{19}{13}\)

= \(\left(\frac{3}{5}+\frac{2}{5}\right)\)+\(\left(\frac{7}{13}+\frac{19}{13}\right)\)+5 +\(\frac{16}{11}\)

=1+2+5+\(\frac{16}{11}\)

=...

3/5 + 5/1 + 7/13 + 2/5 +16 /11+19/13

= (3/5+2/5)+(5/1+16/11)+(7/13+19/13)

=1+21/11+28/13

bạn tự tính tiếp nhé tiếp theo dễ lắm

Lời giải:

\(\frac{3}{4}\times \frac{8}{9}\times \frac{15}{16}\times ....\times \frac{99}{100}\)

\(=\frac{3\times 8\times 15\times ....\times 99}{4\times 9\times 16\times ....\times 100}\)

\(=\frac{(1\times 3)\times (2\times 4)\times (3\times 5)\times ...\times (9\times 11)}{2\times 2\times 3\times 3\times 4\times 4\times ....\times 10\times 10}\)

\(=\frac{(1\times 2\times 3\times ...\times 9)\times (3\times 4\times 5\times ....\times 11)}{(2\times 3\times 4\times....\times 10)\times (2\times 3\times 4\times ...\times 10)}\)

\(=\frac{1\times 2\times 3\times ....\times 9}{2\times 3\times 4\times ....\times 10}\times \frac{3\times 4\times 5\times ...\times 11}{2\times 3\times 4\times ...\times 10}\)

\(=\frac{1}{10}\times \frac{11}{2}=\frac{11}{20}\)

A=\(2^2-9^3+4^{-2}.16-2.5^2\)
\(=4-729+1-50=-774\)
B=\(\left(2^3.2\right).\dfrac{1}{2}+3^{-2}.3^2-7.1+5\)
\(B=2^4.\dfrac{1}{2}+1-7+5=8+1-7+5=7\)
 

 C = 2^-3 + (5²)³.5^-3 + 4^-3.16 - 2.3² - 105.(\(\dfrac{24}{51}\))⁰

C =  \(\dfrac{1}{8}\) + 5⁶.5^-3 + 4^-3.4² - 2.9 - 105.1

C =  \(\dfrac{1}{8}\) + 5³ + \(\dfrac{1}{4}\) - 18 - 105

C =  (\(\dfrac{1}{8}\) + \(\dfrac{1}{4}\))  - (105 - 125 + 18)

C = \(\dfrac{3}{8}\) - (-20 + 18)

C = \(\dfrac{3}{8}\)  + 2

C = \(\dfrac{19}{8}\)

D = 2^-3 . \(\dfrac{1}{2^{-2}}\).\(\dfrac{2}{3}\) + 4^-2.8 - 7. (\(\dfrac{17}{23}\))⁰ + 19

D = 2^-1.\(\dfrac{2}{3}\) + \(\dfrac{1}{16}\).8 - 7.1 + 19

D = \(\dfrac{1}{3}\) + \(\dfrac{1}{2}\) - 7 + 19

D = \(\dfrac{5}{6}\)  + (19 - 7)

D = \(\dfrac{5}{6}\) + 12

D = \(\dfrac{77}{6}\)

\(M=16\frac{3}{31}-\left(\frac{19}{28}-10\frac{3}{31}\right)\)

\(M=16\frac{3}{31}-\frac{19}{28}-10\frac{3}{31}\)

\(M=\left(16\frac{3}{31}-10\frac{3}{31}\right)-\frac{19}{28}\)

\(M=6-\frac{19}{28}=\frac{149}{28}\)

Bấm Đúng cho mình nhé ! ^^ 

\(M=\left(16\frac{3}{31}-10\frac{3}{31}\right)-\frac{19}{28}\)

\(M=6-\frac{19}{28}\)

\(M=5\frac{28}{28}-\frac{19}{28}\)

\(M=5\frac{9}{28}\)

\(\left(20^2+18^2+16^2+......+4^2+2^2\right)-\left(19^2+17^2+.....+3^2+1^2\right)\)

\(=20^2-19^2+18^2-17^2+......+2^2-1^2\)

\(=\left(20-19\right)\left(20+19\right)+\left(18-17\right)\left(18+17\right)+.......+\left(2-1\right)\left(2+1\right)\)

\(=39+35+....+7+3\)

\(=\left(39+3\right)\left[\left(39-3\right):4+1\right]:2=210\)