Answer:

\(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-\frac{20}{15}+\frac{3}{7}\) (Mình đã sửa đề nhé.)

\(=\left(\frac{15}{34}+\frac{19}{34}\right)+\left(\frac{7}{21}+\frac{3}{7}\right)-\frac{20}{15}\)

\(=1+\left(-1\right)+\frac{3}{7}\)

\(=\frac{3}{7}\)

\(\frac{3}{8}.27\frac{1}{5}-51\frac{1}{5}.38+19\)

\(=\frac{3}{8}\left(-24\right).38+19\)

\(=-342+19\)

\(=-323\)

\(-\frac{2}{7}.\frac{21}{8}.-\frac{7}{2}\)

\(=\left(\frac{-2}{7}.\frac{-7}{2}\right)\frac{21}{8}\)

\(=\frac{21}{8}\)

a) \(\frac{3}{8}.27\frac{1}{5}-51\frac{1}{5}.\frac{3}{8}+19\)

\(=\frac{3}{8}.\left(27\frac{1}{5}-51\frac{1}{5}\right)+19\)

\(=\frac{3}{8}.\left(\frac{136}{5}-\frac{256}{5}\right)+19\)

\(=\frac{3}{8}.\left(-24\right)+19\)

\(=\left(-9\right)+19\)

\(=10.\)

b) \(35\frac{1}{6}:\left(-\frac{4}{5}\right)-45\frac{1}{6}:\left(-\frac{4}{5}\right)\)

\(=\left(35\frac{1}{6}-45\frac{1}{6}\right):\left(-\frac{4}{5}\right)\)

\(=\left(\frac{211}{6}-\frac{271}{6}\right):\left(-\frac{4}{5}\right)\)

\(=\left(-10\right):\left(-\frac{4}{5}\right)\)

\(=\frac{25}{2}.\)

Chúc bạn học tốt!

sao từ 29/5 thành 29/4 v ạ

Dấu " / " là phân số nhé :

a) 5 5/27 + 7/23 + 0,5 - 5/27 + 16/23

= 140/27 + 7/23 + 1/2 - 5/27 + 16/23

= ( 140/27 - 5/27 ) + ( 7/23 + 16/23 ) + 1/2

= 5 + 1 + 1/2

= 6 + 1/2

= 13/2

b) 3/8 . 27 1/5 - 51 .1/5 . 3/8 + 19

= 3/8 . 136/5 - 51 . 1/5 . 3/8 + 19

= 3/8 . ( 136/5 - 1/5 ) - 51 + 19

= 3/8 . 27 - 51 + 19

= 81/8 - 52 + 19

= -183/8

Sorry nha mik sửa lại con B

b) 3/8 . 27 1/5 - 51 . 1/5 . 3/8 + 19

= 3/8 . 136/5 - 51/5 . 3/8 + 19

= 3/8 . ( 136/5 - 51/5 ) + 19

= 3/8 . 17 + 19

= 51/8 + 19

= 203/8

\(a;\left(9^3\right)^3.\left(27^4\right)^5:81^5.3\)

\(=9^9.3.\left(\frac{27^4}{81}\right)^5=3^{18}.\left(\frac{3^{12}}{3^4}\right)^5=3^{18}.\left(3^8\right)^5=3^{18}.3^{40}=3^{58}\)

\(b;2^{11^2}:16^5.\left(4^3.8^2\right)^5=2^{22}:2^{20}.\left(2^6.2^6\right)^5\)

\(=2^2.\left(2^{12}\right)^5=2^2.2^{60}=2^{62}\)

a: ~12.58

b: 10

c:-1

d:55/4

dkr68